Decline of maternal hepatitis A virus antibody levels in infants

Hepatitis A is a common viral infection causing substantial morbidity and mortality. The anti-hepatitis A virus (HAV) vaccination in infants would guarantee control of the infection. However, the immunogenicity of the HAV vaccine in infants could be impaired by the presence of passively acquired maternal HAV antibodies. This study evaluated the prevalence of HAV antibodies in 103 women at delivery and in their babies in the first year of life. Eighteen mothers (17.5%) had anti-HAV serum level >10 mIU ml(-1). In their infants the anti-HAV level was still positive in 11 out of 18 (61.1%) at 12 mo. Two out of 85 infants born to anti-HAV-negative mothers and anti-HAV negative at birth were found to be positive at 5 mo of age. Conclusion: It is proposed that all women be screened at delivery for anti-HAV antibodies. Children born to anti-HAV-negative mothers could be vaccinated early during the first year of life, whereas vaccination could be postponed in children born to anti-HAV-positive mothers, if necessary.     

A simplified schedule to integrate the hepatitis B vaccine into an expanded program of immunization in endemic countries

Objective: To investigate the safety, immunogenicity, and efficacy of a simplified hepatitis B vaccination schedule.Methods: The second dose of hepatitis B vaccine and the first dose of diphtheria-tetanus-pertussis (DTP) vaccine were given simultaneously at age 6 weeks. The second dose of DTP vaccine was given at age 3.5 months. The third dose of DTP vaccine and the third dose of hepatitis B vaccine were given at age 5.5 months. One hundred three infants (group A) born to mothers without hepatitis B surface antigen (HBsAg) received DTP with whole-cell pertussis vaccine. Fifty-five infants (group B) born to mothers with HBsAg and hepatitis B e antigen received DTP with acellular pertussis vaccine.Results: By age 9 months, none of group A and 4 (7%) group B infants were seropositive for HBsAg. The protective efficacy against the hepatitis B carrier state in these infants at high risk was 92%. Antibody to hepatitis B surface antigen was 10 mIU/ml or greater in 99 (96%) of group A infants and in 50 (91%) of group B infants. Both the acellular and whole-cell DTP vaccines were immunogenic, and the incidences of adverse reactions were within an expected and acceptable range.Conclusions: The simplified vaccination schedule to integrate the hepatitis B vaccine into the Expanded Programme of Immunization was safe, immunogenic, and effective. This schedule may improve vaccine compliance and be applied to DTP and hepatitis B combination vaccines now under investigation. (J Pediatr 1997;130:981-6)