Antibody and immune memory persistence post infant hepatitis B vaccination

Abstract

Objectives: This study aimed to evaluate the level of hepatitis B immunity among undergraduate students 23 years after commencement of the nationwide hepatitis B childhood immunization program in Malaysia.

Methods: A total of 402 serum samples obtained from volunteer undergraduate students were screened for the presence of hepatitis B surface antibodies using qualitative ELISA.

Results: Results showed that 62.7% of volunteers had protective anti-hepatitis B surface antigens (≥10 IU/L), of whom 67.9% received three doses of the vaccine. The estimated post-vaccination immunity was found to be at least 20 years, indicating persistent immunity against hepatitis B and a significant association (P < 0.05) with duration of vaccination. Anamnestic response 1 month post-hepatitis B booster was 94.0% and highly significant (P < 0.01). Isolated antihepatitis B core antigen (anti-HBc) prevalence was found to be 5.0%, all having had a positive anamnestic response.

Conclusion: Immunity after primary vaccination with hepatitis B recombinant vaccine persists for at least 20 years post-vaccination, with significant association with the number of vaccinations. Furthermore, the presence of anamnestic response to booster vaccine indicates long-lasting immunity despite decreasing antibody levels; therefore, the need for hepatitis B vaccine boosters may not be of significant benefit after complete infant vaccination.

Keywords: anamnestic response; booster vaccination; hepatitis B vaccination; persistent immunity.

Figure 1

Schematic representation of study flow and outline. Abbreviations: HBsAg, hepatitis B surface antigens; anti-HBs, antibodies against hepatitis B surface antigen; anti-HBc, anti-hepatitis B core antigen; IM, intramuscular.