Evidence dossier · candidate cand-mmr-syncope · VICP program · · DRAFT — not a determination
This is a draft research-tracking dossier, not a determination that MMR 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 B2 B3
C4
Consistency / replication
insufficient_data
missing: B5 B6
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: The retrieved evidence includes one article (PMID 16871116) that lists syncope as a recognized vaccine-related adverse event, but it is a general review of vaccination adverse events, not specifically addressing MMR vaccine or providing case-level detail for syncope. No retrieved evidence directly reports syncope after MMR vaccination.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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: MMR vaccine Syncope (Fainting) case report OR case series Series with objective confirmation pubmed · 5641 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
11 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.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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 evidence found
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) case report OR case series Onset histogram pubmed · 2 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
11 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 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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: The retrieved evidence does not address the temporal plausibility of syncope/fainting following MMR vaccination specifically. One review (PMID 16871116) mentions syncope as a general vaccine-related adverse event in children without specifying MMR or onset latency.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) case report OR case series Temporal plausibility pubmed · 31 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
13 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 23754771 · Human psychopharmacology (2013) — Quality of case reports of adverse drug reactions with psychotropic drugs: a 25-year review.
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 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
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 retrieved evidence addresses MMR vaccine and syncope or onset-interval documentation; retrieved articles focus on other vaccines (COVID-19, HPV, monkeypox) and other adverse events (myocarditis, menstrual changes, autoimmune hepatitis).
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) case report OR case series Onset-interval documentation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
11 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.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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: The retrieved evidence includes a 2006 review (PMID 16871116) that mentions syncope as a rare, mild adverse event following routine childhood immunizations, but does not specifically address MMR vaccine or differential diagnosis exclusion for syncope. No other retrieved evidence discusses syncope or MMR vaccine.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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 no reports of syncope (fainting) recurrence upon rechallenge or re-exposure with MMR vaccine. One article (PMID 16871116) mentions syncope as a general vaccine-related adverse event but does not address rechallenge.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) case report OR case series Rechallenge / re-exposure pubmed · 2 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
11 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.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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: no evidence found
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) case report OR case series Adjudicated by criteria pubmed · 39 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
11 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.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
does_not_resolve 40927603 · Journal of healthcare, science and the h (2024) — The Effects of Covid-19 Vaccination on Menstruation: Are women with underlying reproductive health conditions, particularly black women at a higher risk for vac
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: MMR vaccine Syncope (Fainting) case report OR case series Natural-history consistency pubmed · 103 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
12 retrieved record(s)
does_not_resolve 23041539 · Clinical gastroenterology and hepatology (2012) — Association between nonalcoholic fatty liver disease and risk for hepatocellular cancer, based on systematic review.
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.
ambiguous 30000765 · (2006) — Human Papillomavirus Vaccines.
does_not_resolve 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
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 retrieved evidence directly addresses syncope (fainting) following MMR vaccination; one review mentions syncope as a general vaccine-related adverse event but does not specify MMR or provide controlled attribution.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) case report OR case series No confounding object pubmed · 19 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) alternative diagnosis OR not vaccine-related pubmed · 4052 hits · run 2026-09-07
12 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.
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.
ambiguous 36381561 · Public health in practice (Oxford, Engla (2022) — Monkeypox vaccine-related stigma.
does_not_resolve 36441403 · Current cardiology reports (2022) — COVID-19 Vaccine-Related Myocardial and Pericardial Inflammation.
ambiguous 32809680 · (2026) — Rubella Vaccine.
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: MMR vaccine Syncope (Fainting) anatomic localization Predicted site of injury mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) anatomic localization Local vs systemic distribution mechanism pubmed · 0 hits (0 hits — negative) · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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
mirror: MMR vaccine Syncope (Fainting) 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
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Targeted treatment reverses intervention OR treatment OR reversal pubmed · 15141378 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) No internal contradiction coherence OR latency OR susceptibility pubmed · 870020 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Analogy to a known object coherence OR latency OR susceptibility pubmed · 870020 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Analogy to a known object inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) Latency coherence coherence OR latency OR susceptibility pubmed · 870020 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Latency coherence inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
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: The retrieved evidence does not address MMR vaccine or syncope; it focuses on immune checkpoint inhibitor therapy and large language models for identifying immune-related adverse events.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Pre-specification pre-specified OR adjudicated pubmed · 13548 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Pre-specification post-hoc OR hypothesis-generating only pubmed · 1698 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: MMR vaccine Syncope (Fainting) Contrary-evidence log pre-specified OR adjudicated pubmed · 13548 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Contrary-evidence log post-hoc OR hypothesis-generating only pubmed · 1698 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: MMR vaccine Syncope (Fainting) No temporality-only claim pre-specified OR adjudicated pubmed · 13548 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) No temporality-only claim post-hoc OR hypothesis-generating only pubmed · 1698 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: 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: MMR vaccine Syncope (Fainting) Passive-surveillance role pre-specified OR adjudicated pubmed · 13548 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Passive-surveillance role post-hoc OR hypothesis-generating only pubmed · 1698 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: The retrieved evidence does not mention MMR vaccine, syncope, or dose mapping; it focuses on using large language models and natural language processing to detect immune-related adverse events from immune checkpoint inhibitors and endoscopy-related adverse events from procedure reports.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Dose mapping pre-specified OR adjudicated pubmed · 13548 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Dose mapping post-hoc OR hypothesis-generating only pubmed · 1698 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
does_not_resolve 42692516 · BMJ open (2026) — Natural language processing for detecting endoscopy-related adverse events in free-text procedure reports at a tertiary referral centre in Türkiye: a 10-year re
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: The retrieved evidence does not contain any study addressing the risk of syncope (fainting) following MMR vaccination.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Excess vs baseline incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Excess vs baseline pubmed · 88470 hits · run 2026-09-07
8 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 42264391 · Diabetes research and clinical practice (2026) — The risk of type 1 diabetes mellitus after COVID-19 and influenza infection: A nationwide cohort and self-controlled case series study.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
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 38915009 · BMC medicine (2024) — Sleep and liver function biomarkers in relation to risk of incident liver cancer: a nationwide prospective cohort study.
does_not_resolve 34489307 · Gut (2022) — Non-alcoholic fatty liver disease and incident major adverse cardiovascular events: results from a nationwide histology cohort.
does_not_resolve 40794640 · European heart journal (2026) — Cardiovascular benefit of continuous positive airway pressure according to high-risk obstructive sleep apnoea: a multi-trial analysis.
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 retrieved evidence addresses a self-controlled case series (SCCS) risk ratio for MMR vaccine and syncope (fainting). The retrieved studies cover SCCS methodology, COVID-19, shingles, rotavirus, and other vaccines or outcomes, but none report an SCCS risk ratio for MMR vaccine and syncope.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) SCCS incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk SCCS pubmed · 88578 hits · run 2026-09-07
9 retrieved record(s)
does_not_resolve 34937500 · Expert review of vaccines (2022) — Self-controlled case series design in vaccine safety: a systematic review.
ambiguous 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 39795956 · International journal of molecular scien (2024) — The Potential Metalloestrogenic Effect of Aluminum on Breast Cancer Risk for Antiperspirant Users.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
does_not_resolve 42661284 · Expert review of vaccines (2026) — Stroke risk following BNT162b2 vaccination: a systematic review and meta-analysis of self-controlled case series studies.
does_not_resolve 33880627 · Social psychiatry and psychiatric epidem (2021) — Risk of suicide after a self-poisoning episode: a self-controlled case series study.
does_not_resolve 36696094 · JAMA cardiology (2023) — Association of Rurality With Risk of Heart Failure.
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 retrieved evidence directly addresses an elevated incidence rate ratio (IRR > 1 with 95% CI excluding 1) for syncope (fainting) following MMR vaccination in a pre-specified risk window with age/sex stratification.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Cohort / risk-interval incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Cohort / risk-interval pubmed · 88079 hits · run 2026-09-07
11 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 42264391 · Diabetes research and clinical practice (2026) — The risk of type 1 diabetes mellitus after COVID-19 and influenza infection: A nationwide cohort and self-controlled case series study.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
does_not_resolve 42661284 · Expert review of vaccines (2026) — Stroke risk following BNT162b2 vaccination: a systematic review and meta-analysis of self-controlled case series studies.
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 41284649 · PloS one (2025) — Risk of neurologic or immune-mediated adverse events after COVID-19 diagnosis in the United States.
ambiguous 26004568 · Vaccine (2015) — Deaths following vaccination: What does the evidence show?
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 evidence provides a pooled estimate with quantified heterogeneity (I²) for the association between MMR vaccine and syncope (fainting). The retrieved studies address unrelated vaccines (COVID-19, rotavirus, shingles, influenza) or unrelated outcomes (type 1 diabetes, bleeding, falls, glioma) and do not report a meta-analysis specific to MMR vaccine and syncope.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Meta-analysis / pooling incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Meta-analysis / pooling pubmed · 111910 hits · run 2026-09-07
10 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 42264391 · Diabetes research and clinical practice (2026) — The risk of type 1 diabetes mellitus after COVID-19 and influenza infection: A nationwide cohort and self-controlled case series study.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
does_not_resolve 42661284 · Expert review of vaccines (2026) — Stroke risk following BNT162b2 vaccination: a systematic review and meta-analysis of self-controlled case series studies.
does_not_resolve 34933893 · BMJ (Clinical research ed.) (2021) — Respiratory tract infection and risk of bleeding in oral anticoagulant users: self-controlled case series.
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.
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: The retrieved evidence includes systematic reviews and studies on self-controlled case series (SCCS) designs for vaccine safety, but none specifically address the association between MMR vaccine and syncope (fainting) as a negative-control outcome; no evidence of excess risk for syncope after MMR vaccination is presented.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Negative-control outcomes incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Negative-control outcomes pubmed · 88281 hits · run 2026-09-07
6 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 42264391 · Diabetes research and clinical practice (2026) — The risk of type 1 diabetes mellitus after COVID-19 and influenza infection: A nationwide cohort and self-controlled case series study.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
does_not_resolve 38833248 · JAMA network open (2024) — Valproate Use During Spermatogenesis and Risk to Offspring.
does_not_resolve 40252689 · The Lancet. Global health (2025) — The validity of test-negative design for assessment of typhoid conjugate vaccine protection: comparison of estimates by different study designs using data from
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: The retrieved evidence includes a systematic review of self-controlled case series (SCCS) studies for vaccine safety and two SCCS studies evaluating adverse events after COVID-19 and shingles vaccines, but none of these studies addresses syncope (fainting) after MMR vaccination, and no evidence was found that directly compares MMR vaccine to another antigen for syncope risk.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Other-antigen comparison incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Other-antigen comparison pubmed · 88043 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 23949879 · Tumour biology : the journal of the Inte (2014) — Meta-analysis of the association between GSTT1 null genotype and risk of nasopharyngeal carcinoma in Chinese.
does_not_resolve 26004568 · Vaccine (2015) — Deaths following vaccination: What does the evidence show?
does_not_resolve 23296494 · Molecular biology reports (2013) — Assessment of the association between GSTM1 null genotype and risk of type 2 diabetes.
ambiguous 28671426 · American family physician (2017) — Vaccine Adverse Events: Separating Myth from Reality.
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: MMR vaccine Syncope (Fainting) Absolute risk incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Absolute risk pubmed · 111310 hits · run 2026-09-07
10 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 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 32747412 · Gut (2021) — Major GI bleeding in older persons using aspirin: incidence and risk factors in the ASPREE randomised controlled trial.
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 retrieved evidence directly addresses the risk of syncope (fainting) attributable to the MMR vaccine platform, as distinct from a general vaccine association, using the specified self-controlled case series or platform-specific methods.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Platform split incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Platform split pubmed · 88108 hits · run 2026-09-07
10 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 42264391 · Diabetes research and clinical practice (2026) — The risk of type 1 diabetes mellitus after COVID-19 and influenza infection: A nationwide cohort and self-controlled case series study.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
ambiguous 42661284 · Expert review of vaccines (2026) — Stroke risk following BNT162b2 vaccination: a systematic review and meta-analysis of self-controlled case series studies.
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 36370744 · The Lancet. Child & adolescent health (2023) — Cancer risk with topical calcineurin inhibitors, pimecrolimus and tacrolimus, for atopic dermatitis: a systematic review and meta-analysis.
does_not_resolve 23949879 · Tumour biology : the journal of the Inte (2014) — Meta-analysis of the association between GSTT1 null genotype and risk of nasopharyngeal carcinoma in Chinese.
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 directly investigates the association between MMR vaccine and syncope (fainting) stratified by host structure (age/sex).
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Host-structure stratification incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Host-structure stratification pubmed · 88041 hits · run 2026-09-07
10 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 34933893 · BMJ (Clinical research ed.) (2021) — Respiratory tract infection and risk of bleeding in oral anticoagulant users: self-controlled case series.
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 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
does_not_resolve 22709951 · Vaccine (2012) — Vaccine and Immunization Surveillance in Ontario (VISION) - using linked health administrative databases to monitor vaccine safety.
ambiguous 26004568 · Vaccine (2015) — Deaths following vaccination: What does the evidence show?
does_not_resolve 23296494 · Molecular biology reports (2013) — Assessment of the association between GSTM1 null genotype and risk of type 2 diabetes.
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: The retrieved evidence discusses self-controlled case series (SCCS) and self-controlled risk interval (SCRI) methods for vaccine safety studies, including rotavirus vaccine safety, but no study specifically addresses a documented formulation or component change of the MMR vaccine and its association with Syncope (Fainting).
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Formulation / component change incidence risk cohort OR self-controlled case series pubmed · 945 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no association OR null OR no increased risk Formulation / component change pubmed · 88203 hits · run 2026-09-07
5 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 42264391 · Diabetes research and clinical practice (2026) — The risk of type 1 diabetes mellitus after COVID-19 and influenza infection: A nationwide cohort and self-controlled case series study.
does_not_resolve 38875047 · The International journal of risk & safe (2024) — Self-controlled risk interval study of rotavirus vaccine safety: Findings and implications.
does_not_resolve 41092926 · Lancet (London, England) (2025) — Burden of 375 diseases and injuries, risk-attributable burden of 88 risk factors, and healthy life expectancy in 204 countries and territories, including 660 su
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: MMR vaccine Syncope (Fainting) Formulation natural experiment intervention OR treatment OR reversal pubmed · 15141378 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) Policy / pause signal intervention OR treatment OR reversal pubmed · 15141378 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Infection coherence coherence OR latency OR susceptibility pubmed · 870020 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Infection coherence inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) Dose strength gradient dose-response OR dose effect pubmed · 1299132 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no dose effect OR no dose-response Dose strength gradient pubmed · 111 hits · run 2026-09-07
1 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.
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: MMR vaccine Syncope (Fainting) Dose number gradient dose-response OR dose effect pubmed · 1299132 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no dose effect OR no dose-response Dose number gradient pubmed · 555 hits · run 2026-09-07
4 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 42488947 · Hypertension (Dallas, Tex. : 1979) (2026) — Clinical Modifiers of Salt Sensitivity: A Meta-Regression and Risk Translation Study.
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.
does_not_resolve 42106826 · The international journal of behavioral (2026) — Physical activity, falls, and dementia risk in adults aged ≥ 60: evidence from three cohorts.
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 evidence found
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Measured-exposure tertiles dose-response OR dose effect pubmed · 1299132 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no dose effect OR no dose-response Measured-exposure tertiles pubmed · 0 hits (0 hits — negative) · 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 36090988 · Frontiers in immunology (2022) — A comprehensive analysis of the efficacy and effectiveness of COVID-19 vaccines.
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: MMR vaccine Syncope (Fainting) Organoid concentration curve dose-response OR dose effect pubmed · 1299132 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no dose effect OR no dose-response Organoid concentration curve pubmed · 11 hits · run 2026-09-07
1 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.
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 evidence found
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) EC50 vs Cmax coherence dose-response OR dose effect pubmed · 1299132 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) no dose effect OR no dose-response EC50 vs Cmax coherence pubmed · 0 hits (0 hits — negative) · 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 36090988 · Frontiers in immunology (2022) — A comprehensive analysis of the efficacy and effectiveness of COVID-19 vaccines.
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: MMR vaccine Syncope (Fainting) mechanism Mediator identified in cases in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) mechanism Mediator in healthy vaccinees in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) mechanism Infection contrast in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) mechanism Transfer to recipient in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) mechanism Transfer specificity in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) mechanism Depletion / knockdown in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) mechanism Add-back rescue in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) mechanism Neutralization in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) mechanism Isotype control in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Full product reproduces component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Full product reproduces no effect component isolation pubmed · 0 hits (0 hits — negative) · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 25142448 · Current gene therapy (2014) — Improving DNA vaccine performance through vector design.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
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 does not discuss syncope (fainting) in relation to any vaccine vector or particle backbone, nor does it address MMR vaccine or its components; it focuses on live attenuated measles vaccine strains, bacterial and viral vector design for heterologous antigens, and DNA vaccine optimization, none of which provide data on adverse events such as syncope attributed to a vector/particle alone.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Empty vector / particle component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 25142448 · Current gene therapy (2014) — Improving DNA vaccine performance through vector design.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
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: The retrieved evidence discusses attenuated live measles vaccine strains and viral vector vaccine technologies, but none of the abstracts describe isolated measles, mumps, or rubella antigens reproducing syncope (fainting).
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Antigen alone reproduces component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
does_not_resolve 27384578 · Viruses (2016) — Newcastle Disease Virus as a Vaccine Vector for Development of Human and Veterinary 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: Retrieved evidence discusses attenuated live measles vaccine strains, live bacterial vaccine vectors, and virus-vectored influenza/cancer vaccines, but none address MMR vaccine and syncope (fainting) or reproduce the effect in irrelevant cargo.
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Irrelevant cargo component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
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: no evidence found
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Infection preparation component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 25142448 · Current gene therapy (2014) — Improving DNA vaccine performance through vector design.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer vaccines.
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 evidence found
Cited: (none)
supporting: MMR vaccine Syncope (Fainting) Cytokine / adjuvant mix component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 25142448 · Current gene therapy (2014) — Improving DNA vaccine performance through vector design.
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: MMR vaccine Syncope (Fainting) Component combination component OR antigen OR vector pubmed · 2045214 hits · run 2026-09-07
does_not_resolve 25876176 · Human vaccines & immunotherapeutics (2015) — Progress on adenovirus-vectored universal influenza vaccines.
does_not_resolve 25142448 · Current gene therapy (2014) — Improving DNA vaccine performance through vector design.
does_not_resolve 21952287 · Cancer journal (Sudbury, Mass.) (2011) — Viral vector-based therapeutic cancer 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: MMR vaccine Syncope (Fainting) 2D human cells animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Organoid / chip animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Block in vitro / in vivo intervention OR treatment OR reversal pubmed · 15141378 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) mechanism Host-line dependence in vitro OR patient-derived pubmed · 29239 hits · run 2026-09-07
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: MMR vaccine Syncope (Fainting) Animal, clinical route animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Susceptible animal animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Replication across labs animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Blinded scoring animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Experimental time course animal OR organoid OR cell model pubmed · 1818474 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) 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: MMR vaccine Syncope (Fainting) Susceptibility trait coherence OR latency OR susceptibility pubmed · 870020 hits · run 2026-09-07
mirror: MMR vaccine Syncope (Fainting) Susceptibility trait inconsistent OR contradicts pubmed · 27612 hits · run 2026-09-07
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.