Evidence dossier · candidate cand-influenza-syncope · VICP program · · DRAFT — not a determination
This is a draft research-tracking dossier, not a determination that Influenza (flu) vaccine causes Syncope (Fainting), and not an incidence or legal finding. All evidence is flagged needs_human_review and must be reviewed before any page is published or cited. Every value is grounded in retrieved citations (PMID + retrieval date); unsourced items read "no evidence found / not assessable". Symmetric search: every supporting query has a mirror/null query, and zeros are shown (negative dossiers report the absence of signal).
Claim matrix (C1–C6, computed)
Claim
Label
Status
Missing nodes
C1
Coherent clinical object exists
insufficient_data
missing: A1 A2
C2
Consistent temporal window
insufficient_data
missing: A5
C3
Epidemiologic excess risk
insufficient_data
missing: B1 B3
C4
Consistency / replication
insufficient_data
missing: B5
C5
Specificity (product / dose)
insufficient_data
missing: C1n C2n
C6
Biological mechanism
insufficient_data
missing: E1
Two evidentiary bars apply to the epi nodes/claims (C3, C4): · VICP — preponderance of the evidence. · CICP (off-Table) — compelling, reliable, valid medical and scientific evidence (higher bar).
Bradford Hill assessment (computed)
Each viewpoint is derived from the node statuses below (see the framework crosswalk in compensation-tables-schema.md §8). Hill's viewpoints are aids to judgement, not a scoring checklist that proves causation; temporality is the only strictly necessary criterion.
Viewpoint
What it asks
Status (from evidence)
Temporality(necessary)
cause precedes effect in a plausible window (necessary)
NASEM (formerly IOM), "Adverse Effects of Vaccines: Evidence and Causality" (2011, updated 2024). Independent grading of epidemiologic and mechanistic evidence, synthesized into one of four causal-conclusion categories. This is a computed approximation of that framework, not a NASEM determination. See compensation-tables-schema.md §8bis.
Case-definition standard: no established case definition (needs_human_review — not in spec §1's named-standard list) — governs the case-certainty scale on A1/A2/A6/A8 below. See compensation-tables-schema.md §8ter.
Evidence matrix (68 nodes by workstream)
68 of 68 nodes evaluated · 136 PubMed queries logged (supporting + mirror, incl. zeros). Statuses are computed from retrieved citations; not hand-set.
Definition & attribution 24/24 evaluated
A1 · Case reportsno_data
Measure: New definite object in risk window T Comparator: Pre-vaccination baseline Hit rule: Definite object present, onset in window, competing causes considered
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Case reports pubmed · 66171 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
does_not_resolve 34935404 · AJR. American journal of roentgenology (2022) — COVID-19 Vaccine-Related Axillary Adenopathy on Breast Imaging: Follow-Up Recommendations and Histopathologic Findings.
does_not_resolve 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
ambiguous 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
A2 · Series with objective confirmationno_data
Measure: Definite object plus objective test Comparator: Reference range / diagnostic criteria Hit rule: Objective confirmation in >=1 case per the working definition
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Series with objective confirmation pubmed · 5643 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
does_not_resolve 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
ambiguous 7114977 · Archives of internal medicine (1982) — Vaccine-related poliomyelitis.
A3 · Onset histogramno_data
Measure: Distribution of onset times after dose Comparator: Pre-specified risk window Hit rule: Onset clusters inside the pre-specified window (not uniform/flat)
Finding: No retrieved evidence addresses onset clustering of syncope after influenza vaccination; the only relevant PMID (16871116) mentions syncope only as a general adverse event without specific onset timing or distribution data for flu vaccine.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Onset histogram pubmed · 2 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
does_not_resolve 34935404 · AJR. American journal of roentgenology (2022) — COVID-19 Vaccine-Related Axillary Adenopathy on Breast Imaging: Follow-Up Recommendations and Histopathologic Findings.
ambiguous 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
ambiguous 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 7114977 · Archives of internal medicine (1982) — Vaccine-related poliomyelitis.
A4 · Temporal plausibilityno_data
Measure: Onset latency vs object pathophysiology Comparator: Object's known natural latency Hit rule: Onset latency consistent with the object's pathophysiology
Finding: No retrieved evidence specifically addresses temporal plausibility of syncope following influenza vaccine; PMID 16871116 2006 is a general review that mentions syncope as a possible adverse event after routine immunizations but does not provide onset latency data or pathophysiology for influenza vaccine specifically.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Temporal plausibility pubmed · 31 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
10 retrieved record(s)
does_not_resolve 15638050 · Clinical and experimental rheumatology (2004) — A case-series of adverse events, positive re-challenge of symptoms, and events in identical twins following hepatitis B vaccination: analysis of the Vaccine Adv
does_not_resolve 34935404 · AJR. American journal of roentgenology (2022) — COVID-19 Vaccine-Related Axillary Adenopathy on Breast Imaging: Follow-Up Recommendations and Histopathologic Findings.
does_not_resolve 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
ambiguous 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
A5 · Onset-interval documentationno_data
Measure: Onset interval documented in source Comparator: Dose date Hit rule: Onset interval is recorded (not imputed) in a primary source
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Onset-interval documentation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
does_not_resolve 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
A6 · Differential diagnosis excludedno_data
Measure: Competing causes assessed and excluded Comparator: Likely alternative diagnoses Hit rule: Pre-specified competing causes ruled out per the working definition
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Differential diagnosis excluded pubmed · 427 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
ambiguous 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
A7 · Rechallenge / re-exposureno_data
Measure: Object recurs on a further dose Comparator: First-dose response Hit rule: Object recurs after a subsequent dose (re-exposure)
Finding: The retrieved evidence includes a general review of vaccination-related adverse events that mentions syncope as a possible reaction after routine immunizations, but no specific evidence addresses syncope after influenza vaccine rechallenge.
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Rechallenge / re-exposure pubmed · 2 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
ambiguous 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
does_not_resolve 7114977 · Archives of internal medicine (1982) — Vaccine-related poliomyelitis.
A8 · Adjudicated by criteria (no established case definition)no_data
Measure: Object adjudicated by published criteria Comparator: Published clinical / Brighton criteria Hit rule: Cases adjudicated to 'definite' by a published criterion set
Finding: The retrieved evidence includes only a single PMID 16871116 (2006) that mentions syncope in the context of vaccination-related adverse events, but it is a general review of pediatric vaccine adverse events, not specific to influenza vaccine or adjudicated by a published criterion set.
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Adjudicated by criteria pubmed · 39 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
ambiguous 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
ambiguous 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
does_not_resolve 7114977 · Archives of internal medicine (1982) — Vaccine-related poliomyelitis.
A9 · Natural-history consistencyno_data
Measure: Course matches the object's natural history Comparator: Known natural history of the object Hit rule: Clinical course (onset, peak, recovery) matches the object's natural history
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series Natural-history consistency pubmed · 103 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
9 retrieved record(s)
ambiguous 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
does_not_resolve 7114977 · Archives of internal medicine (1982) — Vaccine-related poliomyelitis.
A10 · No confounding objectno_data
Measure: Not attributable to a co-occurring condition Comparator: Co-occurring illness that could produce the object Hit rule: Object not better explained by a co-occurring condition (infection, etc.)
Finding: No evidence was retrieved that directly addresses syncope (fainting) following influenza vaccination, or any assessment of competing causes for such an event.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") case report OR case series No confounding object pubmed · 19 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") alternative diagnosis OR not vaccine-related pubmed · 4053 hits · run 2026-09-07
10 retrieved record(s)
does_not_resolve 34312836 · Clinical pharmacology and therapeutics (2022) — Angiotensin-Converting Enzyme Inhibitors Used Concomitantly with Insulin Secretagogues and the Risk of Serious Hypoglycemia.
does_not_resolve 33647971 · QJM : monthly journal of the Association (2021) — COVID-19 vaccine-related myositis.
does_not_resolve 37775180 · Clinical medicine (London, England) (2023) — SARS-CoV-2 vaccines and myocarditis.
does_not_resolve 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36560483 · Vaccines (2022) — Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?
ambiguous 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 40046048 · Frontiers in immunology (2025) — The protective role of vitamin D in BNT162b2 vaccine-related acute myocarditis.
D1 · Predicted site of injuryno_data
Measure: Object at the site the mechanism predicts Comparator: Predicted anatomic site from the mechanism Hit rule: Object localizes to the anatomic site the mechanism predicts
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") anatomic localization Predicted site of injury mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Predicted site of injury not consistent with mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
D2 · Spared structuresno_data
Measure: Structures the mechanism should spare are spared Comparator: Structures predicted unaffected Hit rule: Structures predicted spared by the mechanism are indeed spared
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") anatomic localization Spared structures mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Spared structures not consistent with mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
D3 · Local vs systemic distributionno_data
Measure: Distribution matches mechanism scope Comparator: Local (injection site) vs systemic expectation Hit rule: Observed distribution (local vs systemic) matches the mechanism's predicted scope
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") anatomic localization Local vs systemic distribution mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Local vs systemic distribution not consistent with mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
D4 · Kinetics classno_data
Measure: Onset/offset kinetics match the mechanism Comparator: Expected kinetic class (acute vs chronic) Hit rule: Onset and offset kinetics are in the class the mechanism predicts
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") anatomic localization Kinetics class mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Kinetics class not consistent with mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
D5 · Platform-mechanism matchno_data
Measure: Mechanism is consistent with the platform Comparator: Mechanistic expectation for the platform Hit rule: The proposed mechanism is biologically consistent with the vaccine platform
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") anatomic localization Platform-mechanism match mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Platform-mechanism match not consistent with mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
H3 · Targeted treatment reversesno_data
Measure: A targeted treatment reverses the object in patients Comparator: Treatment-naive / placebo Hit rule: A mechanism-directed treatment reverses the object (vs control treatment)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Targeted treatment reverses intervention OR treatment OR reversal pubmed · 15142392 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Targeted treatment reverses no effect intervention pubmed · 0 hits (0 hits — negative) · run 2026-09-07
1 retrieved record(s)
does_not_resolve 38189107 · Expert review of vaccines (2024) — Neoadjuvant personalized cancer vaccines: the final frontier?
I1 · No internal contradictionno_data
Measure: No node's finding contradicts another Comparator: Internal consistency across nodes Hit rule: No evaluated node directly contradicts another (coherence)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") No internal contradiction coherence OR latency OR susceptibility pubmed · 870068 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") No internal contradiction inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
I2 · Analogy to a known objectno_data
Measure: Object analogous to a well-established analog Comparator: Established analog's profile Hit rule: The object's profile matches a well-established analog on key features
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Analogy to a known object coherence OR latency OR susceptibility pubmed · 870068 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Analogy to a known object inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
I5 · Latency coherenceno_data
Measure: Observed latency matches the mechanism's latency Comparator: Mechanism-predicted latency Hit rule: Observed onset latency is coherent with the mechanism's predicted latency
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Latency coherence coherence OR latency OR susceptibility pubmed · 870068 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Latency coherence inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
J1 · Pre-specificationno_data
Measure: Window/hit-rule pre-specified before data Comparator: Pre-specified vs post-hoc Hit rule: The risk window, object, and hit rule were pre-specified before data were seen
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Pre-specification pre-specified OR adjudicated pubmed · 13550 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Pre-specification post-hoc OR hypothesis-generating only pubmed · 1700 hits · run 2026-09-07
1 retrieved record(s)
does_not_resolve 39226489 · Journal of clinical oncology : official (2024) — Enhancing Precision in Detecting Severe Immune-Related Adverse Events: Comparative Analysis of Large Language Models and International Classification of Disease
J2 · Contrary-evidence logno_data
Measure: Contrary evidence is logged, not omitted Comparator: Support-only dossier Hit rule: Contrary / null / refuting findings are logged and shown alongside support
Finding: No evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Contrary-evidence log pre-specified OR adjudicated pubmed · 13550 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Contrary-evidence log post-hoc OR hypothesis-generating only pubmed · 1700 hits · run 2026-09-07
1 retrieved record(s)
does_not_resolve 39226489 · Journal of clinical oncology : official (2024) — Enhancing Precision in Detecting Severe Immune-Related Adverse Events: Comparative Analysis of Large Language Models and International Classification of Disease
J3 · No temporality-only claimno_data
Measure: Claim not based on temporality alone Comparator: Sequence-only evidence Hit rule: The claim is not supported by temporal sequence alone (independent evidence exists)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") No temporality-only claim pre-specified OR adjudicated pubmed · 13550 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") No temporality-only claim post-hoc OR hypothesis-generating only pubmed · 1700 hits · run 2026-09-07
1 retrieved record(s)
does_not_resolve 39226489 · Journal of clinical oncology : official (2024) — Enhancing Precision in Detecting Severe Immune-Related Adverse Events: Comparative Analysis of Large Language Models and International Classification of Disease
J4 · Passive-surveillance roleno_data
Measure: Passive-surveillance findings bounded correctly Comparator: Active-surveillance confirmation Hit rule: Passive-surveillance signals are framed as hypothesis-generating, not confirmatory
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Passive-surveillance role pre-specified OR adjudicated pubmed · 13550 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Passive-surveillance role post-hoc OR hypothesis-generating only pubmed · 1700 hits · run 2026-09-07
2 retrieved record(s)
does_not_resolve 39226489 · Journal of clinical oncology : official (2024) — Enhancing Precision in Detecting Severe Immune-Related Adverse Events: Comparative Analysis of Large Language Models and International Classification of Disease
Measure: Dose/lot exposure mapped to the object Comparator: Unmapped exposure Hit rule: Dose / lot exposure is mapped to the object where the mechanism predicts it
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Dose mapping pre-specified OR adjudicated pubmed · 13550 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Dose mapping post-hoc OR hypothesis-generating only pubmed · 1700 hits · run 2026-09-07
1 retrieved record(s)
does_not_resolve 39226489 · Journal of clinical oncology : official (2024) — Enhancing Precision in Detecting Severe Immune-Related Adverse Events: Comparative Analysis of Large Language Models and International Classification of Disease
Epidemiologic chassis 13/13 evaluated
B1 · Excess vs baselineno_data
Measure: RR/IRR vs unexposed or prior window Comparator: Unvaccinated person-time or pre-vaccination window Hit rule: RR/IRR > 1 with CI excluding 1 after pre-specified confounders
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Excess vs baseline incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Excess vs baseline pubmed · 88474 hits · run 2026-09-07
6 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
does_not_resolve 34672967 · Lancet (London, England) (2021) — Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4): a randomised, open-label, parallel-group, multicentre, pha
does_not_resolve 34489307 · Gut (2022) — Non-alcoholic fatty liver disease and incident major adverse cardiovascular events: results from a nationwide histology cohort.
B2 · SCCSno_data
Measure: Self-controlled case series risk ratio Comparator: Individuals' own risk intervals (no-event) Hit rule: SCCS risk ratio > 1 in the post-vaccination window, CI excluding 1
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") SCCS incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk SCCS pubmed · 88582 hits · run 2026-09-07
7 retrieved record(s)
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
does_not_resolve 30851046 · Biostatistics (Oxford, England) (2020) — ConvSCCS: convolutional self-controlled case series model for lagged adverse event detection.
does_not_resolve 40664645 · Nature communications (2025) — Evaluating the safety of XBB.1.5-containing COVID-19 mRNA vaccines using a self-controlled case series study.
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 39795956 · International journal of molecular scien (2024) — The Potential Metalloestrogenic Effect of Aluminum on Breast Cancer Risk for Antiperspirant Users.
supports_node 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
does_not_resolve 30941541 · Cancer causes & control : CCC (2019) — Diabetes, obesity, and subsequent risk of postmenopausal breast cancer among white and black women in the Southern Community Cohort Study.
B3 · Cohort / risk-intervalno_data
Measure: Incidence rate ratio in defined window Comparator: Pre-specified risk vs comparison interval Hit rule: IRR > 1 in the pre-specified window, CI excluding 1, stratified by age/sex
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Cohort / risk-interval incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Cohort / risk-interval pubmed · 88083 hits · run 2026-09-07
5 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
does_not_resolve 40716143 · Vaccine (2025) — Tinnitus risk after COVID-19 XBB.1.5 vaccination: A self-controlled case series study.
ambiguous 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
B4 · Meta-analysis / poolingno_data
Measure: Pooled effect across studies Comparator: Pooled estimate with heterogeneity Hit rule: Pooled estimate > 1 (or < 1) with quantified heterogeneity (I2)
Finding: No retrieved PMID provides a pooled estimate of syncope risk after influenza vaccination with quantified heterogeneity (I2). The retrieved studies either do not address this specific vaccine-adverse event pair, use self-controlled case series designs without meta-analysis, or review unrelated topics.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Meta-analysis / pooling incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Meta-analysis / pooling pubmed · 111920 hits · run 2026-09-07
7 retrieved record(s)
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
does_not_resolve 40664645 · Nature communications (2025) — Evaluating the safety of XBB.1.5-containing COVID-19 mRNA vaccines using a self-controlled case series study.
does_not_resolve 29402646 · Journal of the American Medical Director (2018) — Fall-Risk-Increasing Drugs: A Systematic Review and Meta-analysis: III. Others.
ambiguous 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
does_not_resolve 28230042 · Journal of cancer research and therapeut (2016) — Meta-analysis of association between mobile phone use and glioma risk.
does_not_resolve 25502106 · International journal of epidemiology (2015) — Risk factors for pancreatic cancer: a summary review of meta-analytical studies.
does_not_resolve 28671426 · American family physician (2017) — Vaccine Adverse Events: Separating Myth from Reality.
B5 · Negative-control outcomesno_data
Measure: No excess for outcomes the vaccine should not cause Comparator: Negative-control outcomes (unaffected by mechanism) Hit rule: Null for negative-control outcomes while target outcome is positive (specificity)
Finding: No retrieved evidence addresses syncope (fainting) following influenza vaccination; the provided studies focus on antipsychotic cardiovascular risk, vaccine safety SCCS methodology, herpes zoster vaccine safety, and valproate spermatogenesis, none of which are relevant to this node.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Negative-control outcomes incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Negative-control outcomes pubmed · 88285 hits · run 2026-09-07
4 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
does_not_resolve 38833248 · JAMA network open (2024) — Valproate Use During Spermatogenesis and Risk to Offspring.
B6 · Other-antigen comparisonno_data
Measure: Risk vs a different-antigen comparator Comparator: Comparator product with a different antigen Hit rule: Risk specific to the target antigen, not shared with the comparator antigen
Finding: No evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Other-antigen comparison incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Other-antigen comparison pubmed · 88047 hits · run 2026-09-07
5 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
refutes_node 40716143 · Vaccine (2025) — Tinnitus risk after COVID-19 XBB.1.5 vaccination: A self-controlled case series study.
ambiguous 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
B7 · Absolute riskno_data
Measure: Per-100k risk in window Comparator: Absolute incidence per 100k Hit rule: Absolute risk reported and stable across the window (not an artifact of rarity)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Absolute risk incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Absolute risk pubmed · 111321 hits · run 2026-09-07
9 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
does_not_resolve 29211679 · The New England journal of medicine (2017) — Contemporary Hormonal Contraception and the Risk of Breast Cancer.
does_not_resolve 23484825 · The New England journal of medicine (2013) — Risk of ischemic heart disease in women after radiotherapy for breast cancer.
does_not_resolve 26950145 · Nutrients (2016) — An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity.
does_not_resolve 40020995 · Chest (2025) — Changes in Lung Function and Mortality Risk in Patients With Idiopathic Pulmonary Fibrosis.
does_not_resolve 41707896 · American journal of obstetrics and gynec (2026) — Combined impact of first-trimester risk and aspirin adherence on preterm preeclampsia prevention.
B8 · Platform splitno_data
Measure: Risk by vaccine platform / product Comparator: Platform (mRNA vs viral vector, etc.) Hit rule: Risk attributable to a specific platform, not to 'a vaccine' generally
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Platform split incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Platform split pubmed · 88112 hits · run 2026-09-07
5 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
does_not_resolve 30851046 · Biostatistics (Oxford, England) (2020) — ConvSCCS: convolutional self-controlled case series model for lagged adverse event detection.
refutes_node 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
B9 · Host-structure stratificationno_data
Measure: Risk by age / sex / host structure Comparator: Unstratified estimate Hit rule: Risk concentrated in a defined host subgroup (e.g. young males), stable across sources
Finding: No retrieved evidence addresses syncope (fainting) after influenza vaccination, nor does any study examine risk stratification by age, sex, or host structure for this outcome.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Host-structure stratification incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Host-structure stratification pubmed · 88045 hits · run 2026-09-07
4 retrieved record(s)
does_not_resolve 40716143 · Vaccine (2025) — Tinnitus risk after COVID-19 XBB.1.5 vaccination: A self-controlled case series study.
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
ambiguous 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
B10 · Formulation / component changeno_data
Measure: Risk tracks a formulation change Comparator: Pre- vs post-change formulation Hit rule: Risk change tracks a documented formulation / component change over time
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Formulation / component change incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no association OR null OR no increased risk Formulation / component change pubmed · 88207 hits · run 2026-09-07
7 retrieved record(s)
does_not_resolve 34751642 · Epidemiology and psychiatric sciences (2021) — Cardiovascular and metabolic risk of antipsychotics in children and young adults: a multinational self-controlled case series study.
does_not_resolve 37468475 · Nature communications (2023) — Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.
does_not_resolve 40716143 · Vaccine (2025) — Tinnitus risk after COVID-19 XBB.1.5 vaccination: A self-controlled case series study.
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
refutes_node 42372279 · Annals of internal medicine (2026) — Adverse Events After Same-Day COVID-19 and Influenza Vaccination Versus Influenza Vaccination Alone : A Target Trial Emulation.
ambiguous 28671426 · American family physician (2017) — Vaccine Adverse Events: Separating Myth from Reality.
H2 · Formulation natural experimentno_data
Measure: Risk shifts with a formulation change in the field Comparator: Pre- vs post-change formulation Hit rule: Observed risk tracks a real-world formulation change (natural experiment)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Formulation natural experiment intervention OR treatment OR reversal pubmed · 15142392 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Formulation natural experiment no effect intervention pubmed · 0 hits (0 hits — negative) · run 2026-09-07
1 retrieved record(s)
does_not_resolve 38189107 · Expert review of vaccines (2024) — Neoadjuvant personalized cancer vaccines: the final frontier?
H4 · Policy / pause signalno_data
Measure: Risk signal appears/disappears across a pause or policy change Comparator: Pre- vs post-pause period Hit rule: The signal appears or disappears coherently with a rollout / pause (H4)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Policy / pause signal intervention OR treatment OR reversal pubmed · 15142392 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Policy / pause signal no effect intervention pubmed · 0 hits (0 hits — negative) · run 2026-09-07
I3 · Infection coherenceno_data
Measure: Pattern is coherent with or distinct from infection Comparator: Infection-matched comparison Hit rule: The post-vaccine pattern is coherent with (or clearly distinct from) the infection pattern
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Infection coherence coherence OR latency OR susceptibility pubmed · 870068 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Infection coherence inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
1 retrieved record(s)
does_not_resolve 15578364 · Clinical infectious diseases : an offici (2004) — Varicella vaccine for susceptible adults: do it today.
Mediator & biological gradient 24/24 evaluated
C1n · Dose strength gradientno_data
Measure: Risk vs dose strength (dose size) Comparator: Lower dose strength Hit rule: Monotonic dose-response in dose strength (larger dose -> higher risk)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Dose strength gradient dose-response OR dose effect pubmed · 1299193 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no dose effect OR no dose-response Dose strength gradient pubmed · 117 hits · run 2026-09-07
2 retrieved record(s)
does_not_resolve 39082700 · The Journal of infectious diseases (2025) — Effectiveness of MenB-4C Vaccine Against Gonorrhea: A Systematic Review and Meta-analysis.
does_not_resolve 34505706 · Journal of the American Geriatrics Socie (2021) — Association between vitamin D status and long-term falls-related hospitalization risk in older women.
C2n · Dose number gradientno_data
Measure: Risk vs dose number (1st vs 2nd vs 3rd) Comparator: First dose Hit rule: Risk increases (or shows a defined pattern) with dose number
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Dose number gradient dose-response OR dose effect pubmed · 1299193 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no dose effect OR no dose-response Dose number gradient pubmed · 561 hits · run 2026-09-07
2 retrieved record(s)
does_not_resolve 39082700 · The Journal of infectious diseases (2025) — Effectiveness of MenB-4C Vaccine Against Gonorrhea: A Systematic Review and Meta-analysis.
does_not_resolve 30316563 · Radiotherapy and oncology : journal of t (2019) — Volume effects of radiotherapy on the risk of second primary cancers: A systematic review of clinical and epidemiological studies.
C3n · Measured-exposure tertilesno_data
Measure: Risk vs measured exposure tertile Comparator: Lowest-exposure tertile Hit rule: Risk ordered by measured-exposure tertile (high > mid > low)
Finding: No retrieved evidence addresses the relationship between influenza vaccine and syncope (fainting) or provides data on risk ordered by measured-exposure tertile. The PMIDs retrieved include a meta-analysis of MenB-4C vaccine for gonorrhea, a safety study of high-dose vs. standard-dose influenza vaccine in ESRD patients (but not reporting syncope by exposure tertile), Australian AEFI surveillance (focusing on HPV vaccine), a study of pH1N1 vaccine in egg-allergic children (not syncope), ACIP recommendations (no syncope data), and a COVID-19 vaccine study in pregnant/breastfeeding physicians.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Measured-exposure tertiles dose-response OR dose effect pubmed · 1299193 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no dose effect OR no dose-response Measured-exposure tertiles pubmed · 6 hits · run 2026-09-07
7 retrieved record(s)
does_not_resolve 39082700 · The Journal of infectious diseases (2025) — Effectiveness of MenB-4C Vaccine Against Gonorrhea: A Systematic Review and Meta-analysis.
ambiguous 32565346 · Vaccine (2020) — Comparative safety of high-dose versus standard-dose influenza vaccination in patients with end-stage renal disease.
does_not_resolve 19374268 · Communicable diseases intelligence quart (2008) — Annual report: surveillance of adverse events following immunisation in Australia, 2007.
ambiguous 21714318 · Canadian journal of public health = Revu (2011) — Administration of the adjuvanted pH1N1 vaccine in egg-allergic children at high risk for influenza A/H1N1 disease.
does_not_resolve 30141464 · MMWR. Recommendations and reports : Morb (2018) — Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices-United States, 2018-19 Influenza
does_not_resolve 31441906 · MMWR. Recommendations and reports : Morb (2019) — Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices - United States, 2019-20 Influen
ambiguous 35944074 · Human vaccines & immunotherapeutics (2022) — Adherence to and early adverse events of COVID-19 vaccine in a cohort of 600 Italian breastfeeding and pregnant physicians.
C4n · Organoid concentration curveno_data
Measure: Effect vs antigen concentration in organoid Comparator: Vehicle / zero antigen Hit rule: Dose-dependent effect across a graded concentration curve
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Organoid concentration curve dose-response OR dose effect pubmed · 1299193 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no dose effect OR no dose-response Organoid concentration curve pubmed · 17 hits · run 2026-09-07
5 retrieved record(s)
does_not_resolve 39082700 · The Journal of infectious diseases (2025) — Effectiveness of MenB-4C Vaccine Against Gonorrhea: A Systematic Review and Meta-analysis.
does_not_resolve 32565346 · Vaccine (2020) — Comparative safety of high-dose versus standard-dose influenza vaccination in patients with end-stage renal disease.
does_not_resolve 31441906 · MMWR. Recommendations and reports : Morb (2019) — Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices - United States, 2019-20 Influen
does_not_resolve 19374268 · Communicable diseases intelligence quart (2008) — Annual report: surveillance of adverse events following immunisation in Australia, 2007.
does_not_resolve 30141464 · MMWR. Recommendations and reports : Morb (2018) — Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices-United States, 2018-19 Influenza
C5n · EC50 vs Cmax coherenceno_data
Measure: Measured exposure reaches effect threshold Comparator: Pharmacokinetic Cmax vs EC50 Hit rule: Achieved exposure (Cmax/tissue) plausibly reaches the in-vitro EC50
Finding: No retrieved evidence addresses the coherence between EC50 and Cmax/tissue exposure for influenza vaccine and syncope, nor does any evidence report measured exposures reaching an effect threshold for syncope after influenza vaccination.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") EC50 vs Cmax coherence dose-response OR dose effect pubmed · 1299193 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") no dose effect OR no dose-response EC50 vs Cmax coherence pubmed · 6 hits · run 2026-09-07
7 retrieved record(s)
does_not_resolve 39082700 · The Journal of infectious diseases (2025) — Effectiveness of MenB-4C Vaccine Against Gonorrhea: A Systematic Review and Meta-analysis.
does_not_resolve 32565346 · Vaccine (2020) — Comparative safety of high-dose versus standard-dose influenza vaccination in patients with end-stage renal disease.
does_not_resolve 31441906 · MMWR. Recommendations and reports : Morb (2019) — Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices - United States, 2019-20 Influen
ambiguous 19374268 · Communicable diseases intelligence quart (2008) — Annual report: surveillance of adverse events following immunisation in Australia, 2007.
does_not_resolve 21714318 · Canadian journal of public health = Revu (2011) — Administration of the adjuvanted pH1N1 vaccine in egg-allergic children at high risk for influenza A/H1N1 disease.
does_not_resolve 30141464 · MMWR. Recommendations and reports : Morb (2018) — Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices-United States, 2018-19 Influenza
does_not_resolve 35944074 · Human vaccines & immunotherapeutics (2022) — Adherence to and early adverse events of COVID-19 vaccine in a cohort of 600 Italian breastfeeding and pregnant physicians.
E1 · Mediator identified in casesno_data
Measure: Mediator present in affected tissue/cells Comparator: Unaffected tissue / control Hit rule: The hypothesized mediator is detected in the affected compartment and not (or less) in control
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Mediator identified in cases in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Mediator identified in cases not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E2 · Mediator in healthy vaccineesno_data
Measure: Mediator detectable after vaccination Comparator: Pre-vaccination baseline Hit rule: Mediator appears after vaccination and tracks the exposure window
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Mediator in healthy vaccinees in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Mediator in healthy vaccinees not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E3 · Infection contrastno_data
Measure: Mediator absent/low after natural infection Comparator: Recovered natural infection Hit rule: Mediator signal is specific to vaccination vs a comparable natural-infection control
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Infection contrast in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Infection contrast not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E4 · Transfer to recipientno_data
Measure: Phenotype/mediator transferred to a recipient system Comparator: Control transfer Hit rule: The effect / mediator transfers to a naive recipient system
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Transfer to recipient in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Transfer to recipient not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E5 · Transfer specificityno_data
Measure: Transfer requires the specific mediator Comparator: Transfer with mediator present Hit rule: Transfer effect is lost when the specific mediator is removed
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Transfer specificity in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Transfer specificity not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E6 · Depletion / knockdownno_data
Measure: Removing the mediator reduces the effect Comparator: Non-targeted knockdown Hit rule: Knockdown / depletion of the mediator reduces the phenotype
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Depletion / knockdown in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Depletion / knockdown not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E7 · Add-back rescueno_data
Measure: Adding the mediator restores the effect Comparator: Add-back of a control protein Hit rule: Adding back the mediator (not a control) restores the phenotype
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Add-back rescue in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Add-back rescue not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E8 · Neutralizationno_data
Measure: Neutralizing the mediator blocks the effect Comparator: Isotype control Hit rule: Neutralization of the mediator (not an isotype control) blocks the phenotype
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Neutralization in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Neutralization not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
E9 · Isotype controlno_data
Measure: Isotype control does not reproduce the effect Comparator: Active antibody Hit rule: An isotype control fails to reproduce the block/activation
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Isotype control in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Isotype control not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
F1 · Full product reproducesno_data
Measure: Full vaccine product reproduces the effect Comparator: No-product control Hit rule: The full product (not a subcomponent) reproduces the effect
Finding: No evidence found that directly addresses the full Influenza vaccine product causing syncope; retrieved evidence discusses vaccine vector technologies for other pathogens, not syncope after influenza vaccination.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Full product reproduces component OR antigen OR vector pubmed · 2045311 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Full product reproduces no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 15174971 · Expert opinion on biological therapy (2004) — Particle-mediated DNA vaccine delivery to the skin.
does_not_resolve 29550258 · Immunology letters (2018) — Live bacterial vaccine vector and delivery strategies of heterologous antigen: A review.
F2 · Empty vector / particleno_data
Measure: Vector/particle without antigen reproduces (or not) Comparator: Full product Hit rule: Effect attributed to (or excluded from) the vector/particle backbone alone
Finding: The retrieved evidence describes viral vectors (Newcastle disease virus, lentivirus, avian paramyxoviruses) used in vaccine development but does not address syncope (fainting) attributed to an influenza vaccine vector/particle backbone.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Empty vector / particle component OR antigen OR vector pubmed · 2045311 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Empty vector / particle no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 15174971 · Expert opinion on biological therapy (2004) — Particle-mediated DNA vaccine delivery to the skin.
does_not_resolve 29550258 · Immunology letters (2018) — Live bacterial vaccine vector and delivery strategies of heterologous antigen: A review.
F3 · Antigen alone reproducesno_data
Measure: Isolated antigen reproduces the effect Comparator: Vehicle Hit rule: The isolated antigen (not the full product) reproduces the effect
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Antigen alone reproduces component OR antigen OR vector pubmed · 2045311 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Antigen alone reproduces no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
5 retrieved record(s)
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 29550258 · Immunology letters (2018) — Live bacterial vaccine vector and delivery strategies of heterologous antigen: A review.
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
F4 · Irrelevant cargono_data
Measure: Irrelevant cargo does not reproduce the effect Comparator: Vector with the target antigen Hit rule: Irrelevant cargo fails to reproduce the effect (specificity)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Irrelevant cargo component OR antigen OR vector pubmed · 2045311 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Irrelevant cargo no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
7 retrieved record(s)
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 31300111 · Comparative immunology, microbiology and (2019) — Construction of recombinant capripoxviruses as vaccine vectors for delivering foreign antigens: Methodology and application.
does_not_resolve 42172979 · Virology (2026) — Towards the development of a mucosal vectored vaccine against enterovirus D68.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
does_not_resolve 15853721 · Current HIV research (2005) — Non-replicating viral vector-based AIDS vaccines: interplay between viral vectors and the immune system.
does_not_resolve 22683663 · Vaccine (2012) — Malaria vaccines: focus on adenovirus based vectors.
F5 · Infection preparationno_data
Measure: Infection preparation vs product comparison Comparator: Product-derived preparation Hit rule: Effect compares correctly between infection and product preparations
Finding: The retrieved evidence describes the development and use of viral vector-based vaccines for avian influenza, rabies, malaria, and other pathogens, but does not contain any data on syncope (fainting) following influenza vaccination in humans.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Infection preparation component OR antigen OR vector pubmed · 2045311 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Infection preparation no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 15174971 · Expert opinion on biological therapy (2004) — Particle-mediated DNA vaccine delivery to the skin.
does_not_resolve 29550258 · Immunology letters (2018) — Live bacterial vaccine vector and delivery strategies of heterologous antigen: A review.
F6 · Cytokine / adjuvant mixno_data
Measure: Cytokine/adjuvant mix alone reproduces (or not) Comparator: Individual components Hit rule: The effect is (or is not) reproducible by the cytokine/adjuvant mix alone
Finding: No retrieved evidence addresses the effect of cytokine/adjuvant mix alone on syncope after influenza vaccine; all retrieved PMIDs discuss viral vector vaccine development, not cytokine/adjuvant-mediated adverse events.
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Cytokine / adjuvant mix component OR antigen OR vector pubmed · 2045311 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Cytokine / adjuvant mix no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 31300111 · Comparative immunology, microbiology and (2019) — Construction of recombinant capripoxviruses as vaccine vectors for delivering foreign antigens: Methodology and application.
does_not_resolve 42172979 · Virology (2026) — Towards the development of a mucosal vectored vaccine against enterovirus D68.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
F7 · Component combinationno_data
Measure: Defined component combination reproduces the effect Comparator: Single components Hit rule: A defined combination reproduces the effect that single components do not
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Component combination component OR antigen OR vector pubmed · 2045312 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Component combination no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
5 retrieved record(s)
does_not_resolve 34816398 · Methods in molecular biology (Clifton, N (2022) — Avian Paramyxoviruses as Vectors for Vaccine Development.
does_not_resolve 29550258 · Immunology letters (2018) — Live bacterial vaccine vector and delivery strategies of heterologous antigen: A review.
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
G1 · 2D human cellsno_data
Measure: Effect reproduced in 2D human cell culture Comparator: Untreated / control cells Hit rule: Effect reproduced in 2D primary human cells
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") 2D human cells animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") 2D human cells not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
G2 · Organoid / chipno_data
Measure: Effect reproduced in organoid / organ-on-chip Comparator: Unexposed organoid Hit rule: Effect reproduced in a 3D organoid / organ-on-chip system
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Organoid / chip animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Organoid / chip not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
H1 · Block in vitro / in vivono_data
Measure: Blocking the mediator/mechanism prevents the effect Comparator: Control intervention Hit rule: Blocking the mechanism prevents or reverses the effect (not with a control intervention)
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Block in vitro / in vivo intervention OR treatment OR reversal pubmed · 15142392 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Block in vitro / in vivo no effect intervention pubmed · 0 hits (0 hits — negative) · run 2026-09-07
Clinical / animal / host 7/7 evaluated
E10 · Host-line dependenceno_data
Measure: Effect depends on host line/cell type Comparator: Susceptible host line Hit rule: Effect is restricted to a defined host line / genotype, not universal
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") mechanism Host-line dependence in vitro OR patient-derived pubmed · 29244 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Host-line dependence not associated mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
G3 · Animal, clinical routeno_data
Measure: Effect in animal via the clinical route of administration Comparator: Vehicle, same route Hit rule: Effect reproduced in an animal using the clinical route of administration
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Animal, clinical route animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Animal, clinical route not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
G4 · Susceptible animalno_data
Measure: Effect in a susceptible animal model Comparator: Non-susceptible model Hit rule: Effect in a defined susceptible animal model
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Susceptible animal animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Susceptible animal not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
G5 · Replication across labsno_data
Measure: Effect replicated in an independent lab Comparator: Original result Hit rule: The key effect is replicated in an independent laboratory
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Replication across labs animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Replication across labs not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
G6 · Blinded scoringno_data
Measure: Outcomes scored blinded Comparator: Unblinded reference Hit rule: Primary outcomes scored by a blinded assessor
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Blinded scoring animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Blinded scoring not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
G7 · Experimental time courseno_data
Measure: Effect follows a defined experimental time course Comparator: No-exposure time course Hit rule: The effect's onset/offset follows a defined experimental time course
Finding: no evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Experimental time course animal OR organoid OR cell model pubmed · 1818663 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Experimental time course not reproduced model pubmed · 0 hits (0 hits — negative) · run 2026-09-07
I4 · Susceptibility traitno_data
Measure: A host trait / marker defines susceptibility Comparator: Trait-negative hosts Hit rule: A defined host trait / marker enriches for susceptibility
Finding: No evidence found
Cited: (none)
supporting: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Susceptibility trait coherence OR latency OR susceptibility pubmed · 870068 hits · run 2026-09-07
mirror: Influenza (flu) vaccine (syncope OR fainting OR "vasovagal") Susceptibility trait inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
2 retrieved record(s)
ambiguous 15578364 · Clinical infectious diseases : an offici (2004) — Varicella vaccine for susceptible adults: do it today.
does_not_resolve 19477561 · Vaccine (2009) — Genetic polymorphisms in host response to meningococcal infection: the role of susceptibility and severity genes.
How this was built
Per node: a supporting and a mirror PubMed query built from the node's measure / population / comparator / hit_rule; top hits fetched (title + abstract); each record classified (supports / refutes / ambiguous) by xAI with a heuristic fallback; a per-node synthesis is generated strictly from the retrieved PMIDs; the node status is then rolled up to C1–C6. Full query provenance is shown per node above. Reproduce the build: python -m evidence_run. Data: data/evidence_run/state.json.