Timing of post-vaccination tests in infants born to mothers with chronic hepatitis B virus infection

Abstract

Immunoprophylaxis is routinely recommended for infants born to mothers with hepatitis B virus (HBV) infection within the first 12-24 hours. Detection of hepatitis B surface antibody (HBsAb) resulting from hepatitis B immunoglobulin administered at birth may be perceived as a real vaccine response. This makes it difficult to detect HBV infection. For this reason, it is recommended that infants born to hepatitis B surface antigen positive mothers and who received immunoprophylaxis at birth should have HBsAb testing when they are 9-15 months old.

Key Words: Hepatitis B virus; Infant; Hepatitis B vaccine; Hepatitis B hyperimmune globulin; Vaccination

Core Tip: Infants born to hepatitis B surface antigen positive mothers and who received immunoprophylaxis at birth should have hepatitis B surface antibody testing when they are 9-15 months old.

TO THE EDITOR

We read with great interest the original article by Dirir et al[1] entitled “Immunoprophylaxis failure and vaccine response in infants born to mothers with chronic hepatitis B infection in Djibouti”. In their article, the efficacy of hepatitis B virus (HBV) vaccination combined with one dose of immunoglobulin was evaluated in children born to hepatitis B surface antigen (HBsAg) positive mothers in Djibouti city. They reported that they followed all infants who had received hepatitis B immunoglobulin (HBIG) and vaccination against HBV at birth in a prospective cohort until 7 months of age to assess immunoprophylaxis failure[1].

QUESTION

However, we would like to draw attention to an important situation regarding the timing of post vaccination testing of infants in this study. The timing of post-vaccination tests recommended for infants of HBsAg-positive mothers is different from this and post-vaccination tests are recommended to be performed when they are 9-15 months old[2]. Because, it is aimed to prevent passive hepatitis B surface antibody (HBsAb) detection from HBIG administered at birth and to maximize the possibility of detecting late HBV infection, testing before nine months is not recommended[3].

CONCLUSION

We agree with all the views presented in this article. However, since HBsAb levels were tested at 7 months of age, there is the possibility of passive HBsAb detection from HBIG administered at birth. Therefore, we believe that the HBsAb levels measured in infants may be slightly lower than their true values. To avoid passive detection of HBsAb from HBIG administered at birth and to maximize the likelihood of detecting late HBV infection, we believe that performing postvaccination testing at 9–15 months of age, as recommended in the 2018 American Association for the Study of Liver Diseases hepatitis B guidance[2], will avoid potential confounds in guiding management decisions in daily practice.