Name: Hepatitis A Vaccine
Brand: Havrix
SKU: hepatitis-a

1. Basic Information

Disease Protected Against

Hepatitis A is an acute liver infection caused by hepatitis A virus (HAV), transmitted via the fecal-oral route. Illness ranges from asymptomatic (especially in children <6) to acute liver failure (rare; ~0.3–0.5% case-fatality overall; higher in older adults). Unlike hepatitis B and C, HAV does not cause chronic infection. Before vaccination, the U.S. experienced cyclical epidemics every 10–15 years. The last major epidemic was 1995–1996. Universal childhood vaccination was recommended in 2006.

CDC Schedule (U.S., 2025)

Dose	Age	Notes
Dose 1	12–23 months	First dose recommended at 1 year of age
Dose 2	≥6 months after dose 1	2-dose series. Both Havrix and Vaqta are interchangeable.

Source: CDC ACIP, 2025 schedule. Catch-up vaccination recommended for children 2–18 years not previously vaccinated. Also recommended for adults at increased risk and anyone seeking protection.

Documented Adverse Events (HRSA VICP)

The following adverse events are documented by the HRSA Vaccine Injury Compensation Program (VICP) as having a temporal relationship to this vaccine. These are not necessarily confirmed causal relationships, but rather conditions for which claims have been compensated or are presumed caused by the vaccine.

WHO Causality Assessment Methodology

The World Health Organization's Global Advisory Committee on Vaccine Safety (GACVS) uses a 4-level causality classification:

Consistent: Epidemiological studies demonstrate a statistically significant association with temporal specificity and biological plausibility. Replicated across independent populations and study designs.
Indeterminate: Evidence exists but is insufficient to confirm or rule out causality. May be limited by sample size, confounding, or inconsistency across studies.
Inconsistent: Studies have not demonstrated a consistent or convincing association. Evidence against causality outweighs evidence for it.
Unclassifiable: Insufficient data to reach any conclusion. Requires further evidence.

Source: WHO Global Advisory Committee on Vaccine Safety (GACVS), 2021–2025 causality review cycles. See also Institute of Medicine (IOM) Adverse Effects of Vaccines: Evidence and Causality (2012) for pre-COVID vaccine assessments.

Condition	Time Window	Causality Level	HRSA Description
Anaphylaxis	0-1 days	Consistent WHO Determination (2021, 2023): Consistent for all COVID-19 vaccines. Rate: ~2–5 per million doses. Temporal specificity (onset within minutes, consistent with IgE-mediated). Plausible biological mechanism: immediate hypersensitivity to vaccine excipients (PEG for mRNA, polysorbate for adenoviral). Verified via passive surveillance convergence across multiple national systems (VAERS, EudraVigilance, MHRA Yellow Card, TGA DAEN). Biological Mechanism: Not thought to be spike protein mediated; likely polyethylene glycol (PEG) in mRNA vaccines triggers IgE-mediated mast cell degranulation Clinical Evidence: (Kuder et al., 2021); Mechanism: (Risma et al., 2021) Spike Protein Evidence: Not tested	Anaphylaxis occurring within 4 hours following vaccination

Important Notes

HRSA VICP: Conditions listed are documented by HRSA as having temporal relationship to vaccination. Compensation does not imply causation.
Temporal Association: These conditions occurred after vaccination within the specified time window, but other factors may have contributed.
Rarity: Most adverse events are extremely rare. Serious adverse events from vaccines occur in roughly 1-2 per million doses.
Biological Plausibility: Mechanistic evidence is under review and will be integrated in Q3 2026.
Benefit-Risk: This page documents documented injuries. See disease burden pages for context on prevented diseases.

Ingredients (Package Insert)

Structured composition for 2 branded products covered on this page, taken from FDA-approved package inserts (DailyMed / manufacturer prescribing information). Lists are per product — formulations differ by manufacturer and presentation. Click an ingredient name to open its safety-context page when available.

Inactivated Intramuscular (IM) Adjuvant: Amorphous aluminum hydroxyphosphate sulfate No preservative (typical single-dose) AAHS aluminum Formaldehyde Neomycin Adjuvant: Aluminum hydroxide Aluminum hydroxide

Vaqta Merck Sharp & Dohme LLC · Inactivated

Delivery

Route: Intramuscular (IM)

Form: Suspension for injection

Dose volume: 0.5 mL pediatric / 1 mL adult

Presentation: single-dose vial or prefilled syringe

Encapsulation / delivery vehicle

None (no nanoparticle/VLP encapsulation system)

Antigens

Antigen	Type	Amount / dose
Hepatitis A virus, inactivated Strain: CR326F	Inactivated virus	25 U pediatric / 50 U adult

Adjuvants

Amorphous aluminum hydroxyphosphate sulfate — ≈0.225 mg Al / 0.5 mL pediatric

Preservatives

None — Single-dose presentation; label states no preservative.

Excipients & residuals

Ingredient	Category	Amount	Role
Sodium borate	Buffer	35 mcg (pediatric 0.5 mL)	pH stabilizer
Sodium chloride 0.9%	Buffer	vehicle	vehicle
Formaldehyde	Residual (inactivating agent)	<0.8 mcg residual (50 U dose scale)	residual
Bovine albumin	Residual (manufacturing)	<10^-4 mcg residual (50 U scale)	residual
Neomycin	Residual (antibiotic)	trace residual	residual

Latex: Vial stopper contains natural latex rubber (check presentation).

Source: DailyMed · Verified 2026-07-09

Havrix GlaxoSmithKline Biologicals · Inactivated

Delivery

Route: Intramuscular (IM)

Form: Suspension for injection

Dose volume: 0.5 mL pediatric / 1 mL adult

Presentation: single-dose vial or prefilled syringe

Encapsulation / delivery vehicle

None (no nanoparticle/VLP encapsulation system)

Antigens

Antigen	Type	Amount / dose
Hepatitis A virus, inactivated Strain: HM175	Inactivated virus	720 EL.U. pediatric / 1440 EL.U. adult

Adjuvants

Aluminum hydroxide — ≈0.25 mg Al / 0.5 mL pediatric

Preservatives

None — Single-dose presentation; label states no preservative.

Excipients & residuals

Ingredient	Category	Amount	Role
Amino acid supplement	Stabilizer	label quantity	stabilizer
Phosphate-buffered saline components	Buffer	label quantity	buffer
Polysorbate 20	Surfactant	label quantity	surfactant
Formaldehyde	Residual (inactivating agent)	≤0.1 mg residual	residual
Neomycin sulfate	Residual (antibiotic)	≤40 ng residual	residual

Source: FDA package insert · Verified 2026-07-09

ⓘ How to read this section

Ingredient lists are sourced from official package inserts for the specific brands named above. Formulations can change between lots and over time — verify against the current label before any clinical decision. Presence of a substance does not by itself indicate harm; toxicology is dose-, route-, and context-dependent. Browse the full ingredient database: Vaccine Ingredients index.

Causality assessment & potential mechanisms

Conditions below combine WHO-style causality levels with potential biological mechanisms from the site mechanism catalog (ae_mechanisms_catalog.json). HRSA VICP table listing (where shown) indicates a compensable temporal association under U.S. program rules — not automatic proof of causation for every case. Mechanisms are hypothesis-level pathways with graded evidence.

Condition	Time window	Causality	Potential mechanism(s)
Anaphylaxis HRSA table	0–1 days	Very likely / Probable Evidence: High	IgE-mediated hypersensitivity (anaphylaxis) (primary · hypersensitivity) Pre-existing or newly formed IgE against vaccine antigens or excipients (e.g., gelatin, egg proteins, PEG, polysorbate) triggers mast-cell and basophil degranulation with systemic mediator release.
SIRVA	0–2 days	Very likely / Probable Evidence: High	SIRVA — incorrect injection into shoulder structures (primary · procedural) Needle placement into the subdeltoid/subacromial bursa or joint rather than deltoid muscle causes prolonged local inflammation and restricted range of motion (procedural, not antigen-specific).

Framework: WHO causality + HRSA VICP (where applicable) + AE mechanism catalog. Last updated: 2026-07-18. Schema: schemas/vaccine_injury_table.schema.json · Mechanisms: schemas/ae_mechanism.schema.json. Not medical or legal advice.

2. Pre-Licensure Clinical Trial Data

Licensure trial design (ICAN / OpenVAERS)

The table below reproduces ICAN’s No Placebo Table rows for U.S. childhood-schedule products relevant to this page — including the control/comparator used in FDA licensing trials (not always saline placebo). OSMF presents this for transparency; it is not an endorsement of ICAN interpretations.

Vaccine	Brand	Manufacturer	Doses (schedule)	Ages injected	Control / comparator	Placebo	Safety review window
HepA	Havrix	GSK	2	12M 18M	Engerix-B	No	6 months
HepA	Vaqta	Merck	2	12M 18M	AAHS and Thimerosal	No	42 days

Source: OpenVAERS — No Placebo Table · ICAN original PDF · Attribution: Informed Consent Action Network (ICAN) via OpenVAERS · Last fetched: 2026-07-16. For many trials listing '6 months' safety review, ICAN notes review was typically ~30 days post-injection with a phone call at 6 months.

Havrix (GSK) was licensed in 1995; Vaqta (Merck) in 1996. Both are inactivated whole-virus vaccines. The pivotal trial for Vaqta enrolled ~1,000 children in a community with high HAV incidence and demonstrated ~100% efficacy. Havrix efficacy was demonstrated in ~40,000 Thai children (~94–97% efficacy).

Metric	Data
Pre-licensure safety database (combined)	~10,000+ across both products
Efficacy	~94–100% in pivotal trials; seroprotection >97% after 2 doses
Most common reactions	Injection site pain (~20–50%), erythema (~10–20%), fever (~5–10%), headache (~5–15%)

Key Limitations

Pre-licensure trial sizes were modest by modern standards.
Duration of protection is not fully characterized beyond ~20–25 years of follow-up data, though modeling suggests long-term protection.

3. Post-Licensure Safety Data

Hepatitis A vaccines have >30 years of post-licensure safety data. VSD and VAERS surveillance have not identified unexpected safety signals. The vaccine is one of the least reactogenic on the pediatric schedule aside from injection site reactions. IOM (2012) did not identify safety concerns specific to hepatitis A vaccine. No confirmed post-licensure safety signals have been identified.

⚠ Critical Caveat

VAERS data represent unverified reports. A report to VAERS does not mean the vaccine caused the event.

VAERS Reporting Data — Halma & Varon (2025), DARE-SAFE

The DARE-SAFE paper (Halma & Varon, Pharmacoepidemiology 2025, CC BY 4.0) analyzed VAERS reports for vaccines administered in the United States from 2006–2022. The following data are extracted from Table 1 of that paper for this vaccine (Hepatitis A (Havrix + Vaqta combined)):

Metric	Value
U.S. doses administered (2006–2022)	231,034,565
Total VAERS AE reports	30,930
AE reporting rate (per 100,000 doses)	13.4
Total death reports	85
Death reporting rate (per 100,000 doses)	0.0368
AE-to-Death ratio	364:1

Source: Halma, M.; Varon, J. DARE-SAFE. Pharmacoepidemiology. 2025. DOI: 10.3390/pharma4020007. CC BY 4.0. Data from Table 1.

📚 Important Interpretive Caveats (from the paper itself)

Reporting rate ≠ incidence rate. VAERS is a passive, unverified system. A report means someone submitted a claim of temporal association, not a confirmed causal event. The paper is explicit that causality cannot be inferred from these numbers alone.
Reporting behavior is not uniform. More serious, unusual, or media-salient events are reported at much higher rates than mild ones. Products receiving more public, media, legal, and clinical attention (particularly COVID-19 vaccines, which also benefited from V-safe active-surveillance prompts and CICP compensation pathways) generate more reports per dose regardless of true risk.
Age and comorbidity confounding is not adjusted. COVID-19 vaccines were disproportionately administered to elderly and comorbid populations (nursing homes, 65+, high-risk groups in early 2021) with much higher background all-cause mortality than the general child/working-age population. Some fraction of temporally-associated deaths would occur regardless of vaccination, and the paper does not perform a background-rate comparison.
Stimulated reporting is a known, documented phenomenon. Media coverage, plaintiff attorney solicitation, and advocacy campaigns — all independently inflate VAERS reporting propensity. The paper cites this literature but does not correct for it.
Small-denominator rows are unreliable. Rates computed from small denominators (e.g., monovalent measles, DT, mumps, rubella) have enormous statistical uncertainty and should not be compared to vaccines with hundreds of millions of administered doses without noting the wide confidence intervals.

Source: Halma, M.; Varon, J. DARE-SAFE: Denominator-Adjusted Rate Estimates of Substance Adverse Events Frequency Evaluation in Pharmaceuticals and Vaccines. Pharmacoepidemiology. 2025, 4, 7. DOI: 10.3390/pharma4020007. CC BY 4.0.

Passive Surveillance: AE Type Breakdown (Multi-System)

Side-by-side view of U.S. VAERS, Health Canada Canada Vigilance, Japan JADER (PMDA), EU EudraVigilance, and live-scraped international systems via SurVigilance (VigiAccess, Lareb, DAEN, DMA, Medsafe). SurVigilance panels show MedDRA PT mention totals (not individual-case counts). Category assignment uses keyword matching — approximate, not official SOC coding. VAERS ZIP CAPTCHA downloads use this site’s vaers_pipeline.py; FAERS is bulk quarterly ZIP via SurVigilance (not product search).

VAERS (United States)

Canada Vigilance (Canada)

JADER (PMDA, Japan)

EudraVigilance (EU)

No matching vaccine cases in the current EudraVigilance DAP export.

SurVigilance: VigiAccess · Lareb · DAEN · DMA · Medsafe

VigiAccess (WHO)

Lareb (Netherlands)

DAEN (Australia)

DMA (Denmark)

Denmark DMA interactive ADR search is currently offline (Danish Medicines Agency IT transition; public overviews frozen at 12 Mar 2024). Live product PT tables cannot be retrieved until DKMA restores the search. See DKMA notice. Denmark continues to report into EU EudraVigilance (panel above).

Medsafe (New Zealand)

VAERS (U.S., 2006–2024): 74,945 symptom mentions (16.22/100k doses). Largest share: Other / Unclassified (49%), General / Systemic (non-local) (9%), Neurological (8%). Canada Vigilance (CV Online extract): 1,010 reaction mentions in 283 unique reports (70.7% serious (200 of 283 reports)). Largest share: Neurological (20%), General / Systemic (non-local) (11%), Gastrointestinal (8%). JADER (PMDA public CSV extract): 7 reaction mentions in 4 unique reports (0.0% serious (0 of 4 reports)). Largest share: Allergic / Anaphylactic (43%), Gastrointestinal (29%), General / Systemic (non-local) (29%). VigiAccess (WHO): 150,931 reaction-term mentions · search: hepatitis A. Largest share: Other / Unclassified (21%), Injection-site / Local reaction (17%), General / Systemic (non-local) (13%). Lareb (Netherlands): 1,539 reaction-term mentions · search: Hepatitis A vaccine. Largest share: General / Systemic (non-local) (24%), Injection-site / Local reaction (14%), Neurological (14%). DAEN (Australia): 3,877 reaction-term mentions · search: hepatitis A. Largest share: Other / Unclassified (16%), General / Systemic (non-local) (15%), Neurological (15%). Medsafe (New Zealand): 488 reaction-term mentions · search: hepatitis A. Largest share: Gastrointestinal (28%), General / Systemic (non-local) (25%), Injection-site / Local reaction (18%). Cross-database note: All systems are passive and unverified; reporting rates are not directly comparable across countries (different populations, reporting incentives, and lack of dose denominators for Canada/Japan/EU). top VAERS: Other / Unclassified; top Canada Vigilance: Neurological; top JADER: Allergic / Anaphylactic. SurVigilance note: VigiAccess, Lareb, DAEN, DMA, and Medsafe counts are live-scraped MedDRA PT mention totals (not deduplicated individual cases). Data via SurVigilance (GPL-3.0; pip install SurVigilance). Category assignment uses keyword matching on reported reaction terms — approximate and exploratory. Neither database establishes causality.

Compare AE patterns across all vaccines →

Pharmacovigilance Lot Signal Detection — Hypothesis-Generating Only

Multi-system context below. VAERS (U.S.) supports lot-level volume z-scores and seriousness flags by product and lot (2006–2024). Each lot links to a summary with report count, seriousness %, adverse-event pie chart, U.S. state map, and timeline. A signal flag means a statistical threshold was exceeded — not that a lot is unsafe. Full dashboard →

VAERS flags: VOL high report volume (z ≥ 3) · BURST clustered in <90 days · SER serious reports >50%. Lot numbers are voluntary/incomplete in VAERS. Location data is U.S. state only (no postal codes in the public extract).

VAERS (United States) — all lots by product

16,588 reports with usable lot across 1,604 lots · 163 flagged

Loading lot tables…

Other Pharmacovigilance Systems

Lot-level analysis is only possible where reporters supply batch/lot numbers in the public extract. Canada Vigilance, JADER (PMDA, Japan), and most other national systems publish product-level spontaneous reports without lot fields.

Canada Vigilance (Health Canada)

283 unique reports · 1,010 reaction mentions · 70.7% serious (200 of 283 reports). Top categories: Neurological (20%), General / Systemic (non-local) (11%), Gastrointestinal (8%).

Canada Vigilance spontaneous reports are unverified temporal associations. The public CV Online data extract does not include lot or batch numbers, so lot-level signal detection is not possible for this system — only product-level reaction patterns are shown here. No Canadian dose denominators are available. Extract 2026-03-31.

Search Canada Vigilance →

JADER (PMDA, Japan)

4 unique reports · 7 reaction mentions · 0.0% serious (0 of 4 reports). Top categories: Allergic / Anaphylactic (43%), Gastrointestinal (29%), General / Systemic (non-local) (29%).

JADER (Japanese Adverse Drug Event Report database) spontaneous reports are unverified temporal associations; PMDA has not assessed causality per case. The public CSV extract does not include lot or batch numbers, so lot-level signal detection is not possible — only product-level reaction patterns are shown here. Reaction terms in source data use MedDRA/J Preferred Terms. JADER CSV extract pmdacasereport202606 (2026-06). JADER reference (PDF)

Search JADER / PMDA adverse reactions →

No EudraVigilance (EU) summary is mapped for this page.

VigiAccess (WHO)

150,931 MedDRA PT mentions · search: hepatitis A. Top categories: Other / Unclassified (21%), Injection-site / Local reaction (17%), General / Systemic (non-local) (13%).

Live-scraped public portal data via SurVigilance (GPL-3.0). Counts are reaction-term mentions, not deduplicated individual cases. No lot/batch field.

Search VigiAccess (WHO) →

Lareb (Netherlands)

1,539 MedDRA PT mentions · search: Hepatitis A vaccine. Top categories: General / Systemic (non-local) (24%), Injection-site / Local reaction (14%), Neurological (14%).

Live-scraped public portal data via SurVigilance (GPL-3.0). Counts are reaction-term mentions, not deduplicated individual cases. No lot/batch field.

Search Lareb (Netherlands) →

DAEN (Australia)

3,877 MedDRA PT mentions · search: hepatitis A. Top categories: Other / Unclassified (16%), General / Systemic (non-local) (15%), Neurological (15%).

Live-scraped public portal data via SurVigilance (GPL-3.0). Counts are reaction-term mentions, not deduplicated individual cases. No lot/batch field.

Search DAEN (Australia) →

System	Region	Lot data
VAERS	United States	Lot data
Canada Vigilance	Canada	No public lot field
JADER (PMDA, Japan)	Japan	No public lot field
Lareb (Netherlands)	Netherlands	No public lot field
EudraVigilance	European Union	No public lot field
VigiAccess (WHO)	Global	No public lot field
Yellow Card (UK)	United Kingdom	No public lot field
DAEN (Australia)	Australia	No public lot field

All global data sources → · Data schemas →

Active Pharmacovigilance (Defined-Population Surveillance)

Curated findings for Hepatitis A vaccines from active systems (not VAERS). Page inventory last reviewed: 2026-07-10.

ⓘ Active vs. passive — why this pane is separate

The VAERS / multi-system charts above are passive surveillance: spontaneous, unverified reports without a fixed denominator. Active surveillance starts from a defined, enumerated population (EHR/claims or structured post-vaccination surveys), applies pre-specified statistical tests, and asks whether an outcome occurs more often than expected in a risk window versus a comparison window or group. These are not two flavors of the same evidence — active findings are the harder tier that can confirm, refute, or leave under investigation a signal first hinted in passive data. Do not add VAERS report counts to active incidence rates.

○ No signal detected ◐ Signal under investigation ◑ Investigated — not confirmed ● Signal confirmed (true association) – Not currently under active surveillance

CDC Vaccine Safety Datalink (VSD)

Outcome: Pre-specified serious outcomes in pediatric/adult cohorts

Tier 2 ○ No signal detected

Inactivated hepatitis A vaccines are among the least reactogenic routine products. Active post-licensure work has not identified a confirmed rare serious risk that changed routine childhood recommendations.

Population

VSD HepA vaccinees

Risk interval

Study-specific

Comparison

Control intervals

Evaluation period

Post-1990s licensure era

Method

Post-licensure observational monitoring

Sources: CDC VSD

Record last reviewed: 2026-07-10

Update cadence: Tier 1: check AusVaxSafety monthly when public pages update. Tier 2/3: quarterly review around ACIP meetings and PubMed/MMWR; set lastReviewed per record. Source tiers: Tier 1 = public near-real-time dashboards (e.g. AusVaxSafety); Tier 2 = VSD / Sentinel / PRAC-type findings released via ACIP slides, MMWR, or papers (no public VSD raw dashboard); Tier 3 = regulator label/safety communications. Detecting a signal and later classifying it as not confirmed is normal system behavior — not an anomaly to hide or amplify.

4. Documented Adverse Events

Rank-aggregated VAERS signal detection (rankv)

The table below lists vaccine–event pairs that were detected as disproportionality signals by all four base methods used in rankv (GPS, PRR, ROR, BCPNN) on multi-decade VAERS data, then ordered by rank aggregation (Borda average rank; related to the Spearman/GA top-list approach in the rankv paper).

Agg. rank	VAERS product	Preferred term (event)	N	Method ranks (GPS / PRR / ROR / BCPNN)
228	HEP A (VAQTA)	Hepatitis A clinical-coded PT	17	GPS rank 253 (EBGM=14.89); PRR rank 159 (PRR=34.3359); ROR rank 159 (ROR=34.3532); BCPNN rank 261 (IC_LB=2.6484)

Showing up to 15 pairs for this page (clinical-coded terms listed first). Full processed tables: rankv_signals.json.

Methods combined: BCPNN (IC), GPS/EBGM, PRR, ROR — then rank aggregation.
Data: ~30 years of public VAERS (rankv processed tables).
Origin: precisionFDA “Gaining New Insights by Detecting Adverse Event Anomalies” challenge solution.
Caveat: Disproportionality signals are statistical associations in spontaneous reports. They do not establish causality, incidence, or product defect. Many top pairs reflect administration/product-use coding rather than clinical injury.

Source: nanx.me/rankv · Code: github.com/nanxstats/rankv (MIT) · Built: 2026-07-30.

▶ Strong Evidence

Injection site reactions: Pain (20–50%), erythema (10–20%). Self-limited. Strong
Fever: 5–10% (low-grade). Strong
Anaphylaxis: ~1 per million doses. Strong

5. Disease Prevention Benefits

Metric	Pre-Vaccine Era	Post-Vaccine Era
Annual HAV cases (U.S.)	~30,000–60,000 (1980s–1990s); ~57,000 in the 1995 peak	~3,000–6,000 reported cases (2015–2020); >95% reduction from peak
HAV incidence (children)	Highest incidence in children 5–14 years	>98% reduction in vaccinated age cohorts
HAV-related mortality	~100–150 deaths/year	<50 deaths/year

Source: CDC Pink Book; MMWR. However, the U.S. has experienced large person-to-person outbreaks since 2016 among unvaccinated adults (homeless populations, persons who inject drugs, MSM), reminding that population immunity depends on maintaining high vaccination coverage.

Disease Burden Over Time

Reported U.S. disease burden by year. The dashed vertical line marks vaccine introduction. Hover or tap data points for values; use arrow keys when a chart has focus.

ⓘ About these charts: These are accessible SVG line charts with keyboard navigation, hover tooltips, and an underlying data table (expand below). The dashed vertical line marks the year of vaccine introduction. Reported cases undercount true incidence; case definitions, reporting practices, and diagnostic methods have changed over time. See Section 5 for additional context and pre-vs-post era comparisons.

7. Evidence Summary

Hepatitis A vaccine has a well-established safety profile with >30 years of post-licensure data. It is among the least reactogenic vaccines on the pediatric schedule. No significant safety signals have been identified. Effectiveness is high (>94%). The main evidence gap is the duration of protection beyond 25 years, though immunologic memory is expected to provide long-term protection even after antibody levels wane.

8. International Surveillance & Global Data

Quick links to public pharmacovigilance databases and trial registries relevant to Hepatitis A Vaccine. Reporting counts do not establish causality.

Note: Spontaneous reports are unverified observations. Compare with epidemiological studies in Sections 3–6 before drawing conclusions.

9. Curated Adverse Event Literature

Curated peer-reviewed literature linking specific adverse events to Hepatitis A Vaccine. Each entry is a case report, case series, or related safety publication identified via PubMed. Expand Search PubMed for additional literature below to run custom queries.

Disclaimer: Published reports describe observations and associations; they do not establish population incidence or causality.

10. Key References

IOM. Adverse Effects of Vaccines: Evidence and Causality. National Academies Press; 2012.
CDC. Pink Book — Hepatitis A chapter. cdc.gov/pinkbook
Innis BL, et al. Protection against hepatitis A by an inactivated vaccine. JAMA. 1994;271(17):1328–1334. (Havrix pivotal trial)
CDC. VSD. cdc.gov/vaccine-safety/about/vsd.html
CDC/FDA. VAERS. vaers.hhs.gov

1. Basic Information

Disease Protected Against

CDC Schedule (U.S., 2025)

Documented Adverse Events (HRSA VICP)

WHO Causality Assessment Methodology

Important Notes

Ingredients (Package Insert)

Antigens

Adjuvants

Preservatives

Excipients & residuals

Antigens

Adjuvants

Preservatives

Excipients & residuals

Causality assessment & potential mechanisms

2. Pre-Licensure Clinical Trial Data

Licensure trial design (ICAN / OpenVAERS)

Key Limitations

3. Post-Licensure Safety Data

VAERS Reporting Data — Halma & Varon (2025), DARE-SAFE

Passive Surveillance: AE Type Breakdown (Multi-System)

VAERS (United States)

Canada Vigilance (Canada)

JADER (PMDA, Japan)

EudraVigilance (EU)

SurVigilance: VigiAccess · Lareb · DAEN · DMA · Medsafe

VigiAccess (WHO)

Lareb (Netherlands)

DAEN (Australia)

DMA (Denmark)

Medsafe (New Zealand)

Pharmacovigilance Lot Signal Detection — Hypothesis-Generating Only

Other Pharmacovigilance Systems

Canada Vigilance (Health Canada)

JADER (PMDA, Japan)

VigiAccess (WHO)

Lareb (Netherlands)

DAEN (Australia)

Active Pharmacovigilance (Defined-Population Surveillance)

CDC Vaccine Safety Datalink (VSD)

4. Documented Adverse Events

Rank-aggregated VAERS signal detection (rankv)

▶ Strong Evidence

5. Disease Prevention Benefits

Disease Burden Over Time

7. Evidence Summary

8. International Surveillance & Global Data

9. Curated Adverse Event Literature

10. Key References

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