Internal Medicine
Online ISSN : 1349-7235
Print ISSN : 0918-2918
ISSN-L : 0918-2918
Cases of Rapid Hepatitis B Surface Antigen Reduction after COVID-19 Vaccination
Yosuke OsawaTakaaki OhtakeDaisuke SutoTakayuki AkitaHidehiko YamadaYutaka KohgoKazumoto Murata
Author information

2023 Volume 62 Issue 1 Pages 51-57


Objective One of the therapeutic goals for chronic infection with hepatitis B virus is the clearance of hepatitis B surface antigen (HBsAg) from the blood, as a high load of HBsAg has been proposed to induce antigen-specific immunotolerance. To achieve HBsAg reduction, Pegylated interferon and nucleos (t) ide analogs are used to treat chronic hepatitis B. Following the coronavirus disease 2019 (COVID-19) outbreak, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has rapidly spread worldwide, and vaccination with mRNA COVID-19 vaccines has been conducted since 2021 in Japan. We experienced three clinical cases in which HBsAg levels rapidly decreased after injection of the COVID-19 vaccine without any incentive.

Method To examine whether the vaccine administration was involved in the HBsAg reduction, the number of patients with chronic hepatitis B showing a change in the HBsAg levels during the period before the commencement of the COVID-19 vaccination program in Japan (i.e. until the end of 2020; pre-vaccination-program period) was compared to the number of those who showed a change in HBsAg levels after the initiation of the program (i.e. 2021 onwards; post-vaccination-program period).

Results The number of patients whose HBsAg levels was reduced by >50% per year was prominent after the initiation of the vaccination program. Although the involvement of vaccination in HBsAg reduction was not statistically proven (p=0.0532), the result suggests that the administration of COVID-19 vaccines may have been involved in HBsAg reduction in patients with chronic hepatitis B.

Conclusion COVID-19 vaccines may be involved in HBsAg reduction.

Content from these authors
© 2023 by The Japanese Society of Internal Medicine
Previous article Next article