“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

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.117224Chen 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.2023.1100617Joszt 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-goalsUlrich 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