Antibody and immune memory persistence post infant hepatitis B vaccination

Abstract

Shuaibu A Hudu,1,2 Yasmin A Malik,3 Mohd Taib Niazlin,1 Nabil S Harmal,1,4 Ariza Adnan,5 Ahmed S Alshrari,1 Zamberi Sekawi1 1Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia; 2Department of Pathology and Medical Microbiology, College of Health Sciences, Usmanu Danfodiyo University Sokoto, Sokoto State, Nigeria; 3Department of Clinical Science, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Selangor, Malaysia; 4Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen; 5Cluster of Laboratory Medical Sciences, Faculty of Medicine Universiti Teknologi MARA, Sungai Buloh, Selangor, Malaysia 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 anti-hepatitis 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: hepatitis B vaccination, persistent immunity, anamnestic response, booster vaccination