Ludovico Picciotto

Safety and immunogenicity of hepatitis A vaccine in infants: a candidate for inclusion in the childhood vaccination programme

Forty-eight infants received a single dose (720 ELISA units = 0.5 ml) of inactivated hepatitis A vaccine at the fifth month of age with booster at the 11th month of age, together with the second and third doses of the vaccines compulsory under Italian law (diphtheria, tetanus, oral polio and hepatitis B). Overall, the seroconversion rate was 100%. The anti-HAV geometric mean titre (GMT) reached 3,021 mIU/ml in infants born to anti-HAV-negative mothers, but only 399 mIU/ml in infants born to anti-HAV-positive mothers. Hepatitis A vaccine was immunogenic, safe and well tolerated without significant side-effects. There seems to be no reason for not including it in childhood vaccination programmes particularly in low endemic HAV areas.

MASS VACCINATION AGAINST HEPATITIS B IN INFANTS IN ITALY

A field trial currently underway in an area near Naples Italy where hepatitis B is endemic is providing support for a new vaccination protocol that involves administering hepatitis B vaccine at 3 and 5 months of age with a booster at 11 months. This protocol saves 1 dose of vaccine and also allows hepatitis B vaccine to be administered at the same time as immunization against diphtheria tetanus and poliomyelitis. Measurement of anti-hepatitis B surface antigen titers in the 110 Italian infants vaccinated according to this protocol to date revealed seroconversion rates of 93.6% immediately before the 11 month booster and 96.3% 2 months after the booster injection. In addition to being effective this protocol has been highly acceptable. 99% of mothers in the area have complied with the immunization program and have welcomed the opportunity to obtain protection for their children against hepatitis B at the same time that other immunizations are administered. On the basis of these findings the Italian health authorities have adopted the new protocol for routine use in areas highly endemic for hepatitis B infection. The World Health Organization has also recommended that hepatitis B vaccine be offered at the same time as other childhood immunizations.

Effective antibody response in newborn babies living in Maldives to simultaneous vaccination against hepatitis B, poliomyelitis, diphtheria and tetanus

The antibody responses of Maldivian infants early in their life to simultaneous immunization against hepatitis B virus, poliomyelitis, diphtheria and tetanus were investigated. The vaccines were given at 6, 10 and 14 weeks of age. Among 243 newborn babies from HBsAg-negative mothers, 103 received three doses of oral poliomyelitis (OPV) and diphtheria and tetanus (DTV) vaccines; 105 were similarly immunized but received in addition the recombinant hepatitis B vaccine (HBV); 35 were immunized with the HBV recombinant vaccine alone. The antibody response to all of the vaccines was effective. No significant differences among the groups were observed. Hepatitis B vaccination of infants neither affected nor was affected by the contemporary administration of OPV and DTV vaccines.