Acute hepatitis B infections reported among appropriately vaccinated individuals, Philadelphia: A Role for Booster Doses?

Routine newborn and childhood vaccinations for hepatitis B virus (HBV) in the U.S. have driven a decrease in HBV infections. In Philadelphia, reports of acute hepatitis B infections among fully vaccinated individuals prompted further investigation. Among people with reported acute HBV occurring between 2018 and 2023, people born in 1981 or later were matched to vaccination and birth records. Additional data were collected via chart audits for clinical and risk factor information. Fifty-two acute HBV cases occurred between 2018 and 2023 among people born in 1981 or later. Approximately 13.5 % ( n = 7) were known to have completed a three-dose series of HBV vaccination with appropriate dose intervals, six (85.7 %) completed the vaccination series as an infant. All seven cases had clinically and epidemiologically confirmed acute disease. All case persons had an immunocompromising condition, including 66.7 % ( n = 4) with a history of nonmedical substance use documented during the time of acute HBV identification. All three case persons with HIV had evidence of negative hepatitis B surface antigen testing at the time of HIV diagnosis. Breakthrough cases of acute hepatitis B were found among persons who completed the hepatitis B vaccination series since universal vaccination in childhood was recommended. Further characterization of risk factors acquired after completing the series and optimizing hepatitis B immunity in the vaccination process are warranted using large and comprehensive datasets, such as those of health systems.