Neonatal vaccination and HBV prevalence: Evidence from Esfandiar village, Iran

  • Narges Jarrahi Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
  • Arezou Khosrojerdi Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
  • Fereshte Osmani Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
  • Armin Ziaee Student Research Committee, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
  • Masood Ziaee Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
Keywords: Hepatitis B; Immunization programs; Infant; Seroepidemiologic studies; Vaccine efficacy

Abstract

Background and Objectives: Hepatitis B virus (HBV) remains a major public health challenge, particularly in hyperendem- ic regions. This study assessed the effectiveness of Iran's national HBV vaccination program in Esfandiar village, South Kho- rasan Province, where HBV prevalence substantially exceeds the national average. We compared hepatitis B surface antigen (HBsAg) prevalence between cohorts born before and after implementation of the universal vaccination program in 1993. Materials and Methods: We conducted a cross-sectional seroprevalence study encompassing both unvaccinated individuals (born before 1993) and vaccinated individuals (born 1993 onwards) in Esfandiar village. Serum samples were analyzed for HBsAg, hepatitis B e antigen (HBeAg), and hepatitis B core antibody (HBcAb) using enzyme-linked immunosorbent assay (ELISA).

Results: HBsAg prevalence was markedly higher among unvaccinated individuals (22.56%, 132/585) compared to vaccinat- ed individuals (1.19%, 3/252), yielding a vaccine effectiveness of 94.74%. Among vaccinated children, 54% maintained pro- tective antibody titers (>10 mIU/mL), with highest levels observed in children born to HBsAg-positive mothers. Conversely,

46% of vaccinated children demonstrated suboptimal antibody titers (<10 mIU/mL), predominantly among those born to HBsAg-negative mothers. Notably, all three HBsAg-positive vaccinated children were born to mothers with concurrent HBsAg and HBeAg positivity.

Conclusion: The national HBV vaccination program demonstrates remarkable effectiveness in reducing HBsAg prevalence, underscoring the critical importance of universal neonatal immunization in endemic settings. Enhanced preventive strategies, including hepatitis B immunoglobulin (HBIG) administration to infants of HBeAg-positive mothers, could further optimize protection. Sustained surveillance and rigorous adherence to vaccination protocols remain essential for achieving compre- hensive HBV control.

Published
2025-10-13
Section
Articles