Hepatitis A vaccine side effects (Vaqta, Havrix): VAERS data, trials and schedule
This page answers “hep a vaccine side effects” with sourced pharmacovigilance data — VAERS and EudraVigilance case-linked data. Counts are database reports, not proven vaccine-caused injury rates.
How to read database counts: Pharmacovigilance systems (VAERS, EudraVigilance, Yellow Card, VigiBase, Lareb, DAEN) collect spontaneous, unverified reports. A report is not a confirmed adverse event and does not prove the vaccine caused the outcome. Under-reporting, stimulated reporting, and missing denominators limit rate interpretation. Compare with trials and epidemiological studies on each page before drawing conclusions.
Gold Standard EO (Aug 10, 2026)Federal recommendation status: High-risk groups & shared clinical decision-making
The August 10, 2026 Executive Order on Gold Standard Childhood Vaccine Recommendations places hepatitis A in both the Recommended for certain high-risk groups/populations and Based on shared clinical decision-making categories — not a universal recommendation for all children. The EO also expresses a preference, to the maximum extent feasible, for administering all childhood immunizations at separate medical visits. Section 2(a) of the order lists hepatitis A and hepatitis B in both clause (ii), certain high-risk groups or populations, and clause (iii), shared clinical decision-making. The overlap is the order’s own text.
This page summarizes published data for inactivated hepatitis A vaccines on the U.S. childhood schedule (Havrix® and Vaqta®). Universal childhood HepA vaccination was recommended by ACIP in 2006. Data are presented without interpretive language that implies the vaccine is "safe" or "unsafe."
Evidence state
For each outcome: the specific question, what controlled studies found, and how certain that evidence is on the GRADE scale (high, moderate, low, very low). Ratings are editorial judgments by the site applying GRADE to the studies in the table below — observational evidence starts at low and is rated up for large, consistent effects or a dose/age gradient, and down for inconsistency or imprecision (Methods). Where an effect is confined to a subgroup (for example young males), the question says so. "Not searched" means no controlled study has been compiled here yet; it is not a finding that the outcome is rare or caused by the vaccine.
Outcome & question
Finding & certainty
Why this rating
Immune thrombocytopenia
Hepatitis A vaccine, children 7–17
inconclusive Very low certainty
Single study with too few events. Studies: O'Leary 2012.See table
Anaphylaxis
Not searched
No controlled-study result is compiled for this outcome yet.
Myocarditis or pericarditis
Not searched
No controlled-study result is compiled for this outcome yet.
Guillain-Barré syndrome
Not searched
No controlled-study result is compiled for this outcome yet.
Febrile seizure
Not searched
No controlled-study result is compiled for this outcome yet.
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.
Licensed Hepatitis A vaccine products
Each product has its own page with package-insert ingredients, side-effect data, lot lookup and comparisons with the other brands.
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.
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.
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 reports per million doses
U.S. VAERS reports for vaccinations given 2006–2024, divided by the 272 million doses distributed in the same years (HRSA, from CDC data).
All reports
152
per million doses (150–153) · 41,289 reports
Serious reports
8.5
per million doses · 2,303 reports (death, life-threatening, hospitalised or disabled)
Reports with a death
0.58
per million doses · 158 reports
These are reporting rates: they mix real reactions, coincidental events and reports of conditions that would have happened anyway, and they depend on how actively each vaccine is watched. Doses are distributed, not administered. Combination vaccines count toward each component in both numerator and denominator. Compare with the observed-vs-expected analysis and the controlled studies above. Data: vaers_reporting_rates.json.
All vaccines, per million doses
Vaccine
All
Serious
Death
pcv
266
28.1
3.23
rotavirus
157
27.9
4.08
hpv
335
25.3
2.00
hib
126
19.7
3.25
polio
152
17.6
2.77
mmr
320
15.3
0.94
varicella
372
14.1
0.84
hepatitis-b
110
12.7
2.15
meningococcal
214
11.8
0.70
dtap
132
11.2
1.31
hepatitis-a
152
8.5
0.58
influenza
68
5.4
0.48
What controlled safety studies found
Unlike VAERS counts, these studies compare vaccinated people with a control group or control time window, so they can estimate whether a risk is raised and by how much. 1 results for hepatitis A vaccines: 0 found an increased risk of a specific outcome, 0 found no increased risk.
Outcome
Design & population
Estimate (95% CI)
Excess per million doses
Finding
Source
ITP
Hepatitis A vaccine
cohort, risk vs control intervals (VSD) Children 7-17 y, US
Trials on ClinicalTrials.gov with posted results and a placebo, saline or no-vaccine control arm (4,469 vaccinated vs 1,487 controls), pooled with a random-effects model:
Any serious adverse event: RR 1.28 (95% CI 0.89–1.82), 1 trial — no significant difference
Death (any cause, including from the disease itself): not estimable
Safety Study of Herpes Simplex Vaccine in HSV Seronegative and Seropositive Females Betwee
142/4,469
37/1,487
Only blinded, placebo-controlled periods are used (open-label, crossover, booster and extension periods excluded) and vaccine and placebo arms are matched within the same trial part. Risk ratios use participant counts, not person-time: where placebo recipients crossed over to vaccine, the placebo arm is followed for less time, which pushes count-based ratios up. Serious adverse events are sponsor-coded and include events unrelated to vaccination; trials were powered for efficacy, not rare harms; most childhood-vaccine trials use active comparators and therefore do not appear here. Code: analysis/vaccine_trial_meta.py; data: vaccine_trial_meta.json.
When do reported events start? (time to onset)
Days from vaccination to onset in U.S. VAERS reports (0–180 days). A causal reaction usually starts inside a characteristic window; but people also report what happens soon after a shot, so each event is compared with all other reports for this vaccine. The Weibull shape measures bunching (below 1 = most onsets early).
Event
Reports
Median days
In risk window
Shape (95% CI) vs others
Reading
Syncope
1,782
0
96% (others 73%)
0.75 (0.71–0.84) vs 0.66
spread later than other reports
Seizure (any)
1,596
1
95% (others 96%)
0.71 (0.68–0.75) vs 0.66
spread later than other reports
Febrile seizure
525
2
95% (others 96%)
0.86 (0.80–0.93) vs 0.66
spread later than other reports
Guillain-Barré syndrome
141
17
87% (others 47%)
1.14 (1.01–1.35) vs 0.66
spread later than other reports
Anaphylaxis
112
0
94% (others 73%)
0.93 (0.82–1.22) vs 0.66
spread later than other reports
Herpes zoster
110
14.5
57% (others 47%)
0.54 (0.46–0.61) vs 0.66
clusters earlier than other reports
ADEM / encephalitis
72
11
86% (others 47%)
0.89 (0.78–1.01) vs 0.66
spread later than other reports
Immune thrombocytopenia
65
17
88% (others 47%)
1.14 (0.97–1.53) vs 0.66
spread later than other reports
Bell's palsy / facial paralysis
53
4
81% (others 47%)
0.76 (0.65–1.00) vs 0.66
same timing as other reports
Myocarditis / pericarditis
29
3
69% (others 89%)
0.85 (0.66–1.62) vs 0.66
same timing as other reports
Transverse myelitis
27
14
89% (others 47%)
1.13 (0.90–1.63) vs 0.66
spread later than other reports
Stroke
21
3
71% (others 46%)
0.62 (0.50–1.05) vs 0.66
same timing as other reports
Timing alone cannot establish causation; it can make it more or less plausible. *Fitted on a random sample of 5,000 of these reports. Data: vaers_onset.json.
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 files on this site are built from the public VAERS download. FAERS figures use the public quarterly FAERS files. Counts are mentions or reports, not incidence.
VAERS (United States)
Canada Vigilance (Canada)
JADER (PMDA, Japan)
EudraVigilance (EU)
No matching vaccine cases in the current EudraVigilance DAP export.
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.
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.
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)
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.
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.
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).
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.
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.
Common questions
How long do Hepatitis a vaccine side effects last?
Most reported Hepatitis a vaccine reactions are short-lived: injection-site soreness, tiredness, and low-grade fever that typically begin within a day or two and resolve within a few days. Longer-lasting or more serious events are rarer and are the ones tracked in the post-licensure surveillance and documented adverse-event sections of this page, with report counts that are not incidence rates. Anything severe or persisting beyond a week warrants medical review.
Is the Hepatitis a vaccine given to adults, and are side effects different in adults?
Whether the Hepatitis a vaccine is recommended for adults depends on the vaccine and the person's risk factors; the schedule and product sections above describe the licensed indications and age groups. Reporting patterns in adults can differ from children, so this page's VAERS and international database breakdowns should be read with the reporting population in mind. Check the current CDC/ACIP adult schedule and the product's prescribing information for adult dosing.
10. Key References
IOM. Adverse Effects of Vaccines: Evidence and Causality. National Academies Press; 2012.