Postvaccine Hepatitis Reports More Often Serious in Children vs Adults

Hepatitis reports submitted to the Vaccine Adverse Event Reporting System (VAERS) involving children were more likely to be classified as serious than those involving adults, according to a cross-sectional analysis published in Cureus, but the surveillance data cannot show whether any vaccine raises hepatitis risk.¹ In the study, “hepatitis” wasn’t necessarily a clinically confirmed diagnosis but instead referred to any VAERS report coded with the term.

Stratified VAERS Data Address Gap in Hepatitis Research

VAERS, jointly maintained by the CDC and FDA, collects reports of adverse events following vaccination from health care professionals, manufacturers, patients, and the public, regardless of whether they believe the vaccine caused the event. Immune-mediated, autoimmune-like hepatitis has been documented after several COVID-19 vaccines.

Most patients in a multicountry case series had favorable outcomes, but one patient developed fulminant liver failure requiring transplantation. With most evidence coming from case reports and small studies with short follow-up, analyses stratified by age, sex, vaccine type, onset interval, and seriousness have been limited, the investigators noted.

To address this evidence gap, they queried the CDC's Wide-ranging Online Data for Epidemiologic Research interface and extracted reports from 1990 to 2026 coded with the Medical Dictionary for Regulatory Activities Preferred Term "Hepatitis" from data processed through April 24, 2026. The researchers summarized categorical variables using frequency distributions and percentages.

They used Pearson’s chi-square tests to compare serious and nonserious reports by age group, reported sex, and interval from vaccination to symptom onset. The researchers also calculated Cramér’s V to quantify the magnitude of differences between the groups.

Pediatric Reports More Often Classified as Serious

They retrieved 529 hepatitis reports. Of these, 200 (37.8%) reports were classified as serious and 329 (62.2%) as nonserious. VAERS classified serious reports as those listing death, permanent disability, life-threatening event, or hospitalization, including prolonged stays. Hepatitis B vaccines were listed 267 times in a total of 529 reports (50.5%), followed by COVID-19 vaccines (25.3%) and hepatitis A vaccines (6.4%). Because a single report could list multiple products, the researchers noted that these counts represent vaccine listings rather than unique reports.

“One possible explanation for the high number of hepatitis B vaccine listings is its longer history of use and administration across different age groups,” the authors noted.

Reporting peaked in 2021 with 68 reports during widespread COVID-19 vaccination, then fell to 34 in 2022. Mass vaccination, heightened safety monitoring, media coverage, and the Weber effect, in which spontaneous reporting rises after a new product is introduced, may have shaped that pattern, the investigators explained.

Adults aged 18 to 49 years made up the largest group of reports (n = 216; 40.8%), and female sex was recorded more often than male sex (49.3% vs 41.4%). The onset interval was unknown for a large portion of reports (n = 178; 33.7%). Among those whose onset interval was documented, 1 to 3 days was most frequently documented (n = 70; 13.2% of all reports).

Reported outcomes included emergency department or office visits (n = 164; 31.0%), hospitalization (n = 154; 29.1%), life-threatening events (n = 53; 10.0%), permanent disability (n = 29; 5.5%), and death (n = 26; 4.9%). By contrast, “none of the above” was recorded in 184 reports (34.78%).

Age group was significantly associated with seriousness classification (χ²(5) = 21.61; P = .0006), but the Cramér’s V value of 0.224 suggested a modest association between the 2. Two-thirds of the reports for children aged less than 1 year were classified as serious (10 of 15), as were the reports for children aged 1 to 5 years (22 of 33). In addition, 55.1% (27 of 49) of reports for children aged 6 to 17 years, 36.6% (79 of 216) of those among adults aged 18 to 49 years, 32.0% (24 of 75) among those aged 50 to 64 years, and 47.6% (20 of 42) among those 65 years and older were considered serious.

By contrast, neither sex (χ²(1) = 3.84; P = .0502) nor onset interval (χ²(7) = 8.88; P = .2614) was significantly associated with seriousness classification.

More Research Is Needed Amid Hepatitis B Vaccine Debate

The analysis adds to the VAERS research literature. For example, 1 past study published in Frontiers in Pharmacology found an overall reported rate of autoimmune hepatitis after COVID-19 vaccination of 0.21 per million people, concluding that the number of cases reported to VAERS did not suggest a safety concern attributable to the vaccine.²

Hepatitis B vaccination policy is drawing renewed attention after the Advisory Committee on Immunization Practices voted in December 2025 to follow shared clinical decision-making on the hepatitis B birth dose for infants born to mothers who test negative for hepatitis B surface antigen, ending more than 30 years of universal birth-dose guidance.³ Separately, a review published in Pediatrics earlier this year reaffirmed the vaccine's safety at birth, finding no serious adverse events attributable to neonatal vaccination.⁴

The authors acknowledged that the study cannot speak to vaccine-specific risk because VAERS does not capture administered doses.¹ In addition, the small pediatric sample, missing data on age, sex, and onset interval, and the lack of clinical verification further limit interpretation.

“Additional studies utilizing vaccination denominators, appropriate comparative populations, patient-specific clinical data, laboratory test results, and histologic examination are required to determine possible etiologic factors and mechanisms of injury,” the authors concluded.

References

1. Aragón Gutierrez P, Botlaguduru D, Chowdary Medarametla A, Killy SP. Serious and non-serious hepatitis reports in the U.S. Vaccine Adverse Event Reporting System, 1990–2026: a cross-sectional analysis. Cureus. 2026;18(9):e117224. doi:10.7759/cureus.117224
2. Chen C, Xie D, Xiao J. Real-world evidence of autoimmune hepatitis following COVID-19 vaccination: a population-based pharmacovigilance analysis. Front Pharmacol. 2023;14:1100617. doi:10.3389/fphar.2023.1100617
3. Joszt L. Misinformation, access gaps threaten hepatitis B elimination goals. AJMC^®. June 18, 2026. Accessed October 6, 2026. https://www.ajmc.com/view/misinformation-access-gaps-threaten-hepatitis-b-elimination-goals
4. Ulrich AK, Fleming DF, Smith EA, et al. Hepatitis B vaccination at birth: safety, effectiveness, and public health benefit. Pediatrics. Published online February 5, 2026. doi:10.1542/peds.2025-075783