Duration of hepatitis B antibody response in children immunised with hepatitis B and compulsory vaccines.

Twenty four subjects were simultaneously administered DT toxoids, OPV and HBV vaccines at the age of 3, 4-5 and 11 months and then followed up for 2 and 4 years in order to evaluate the duration of the immune response and the need and the timing of HBV revaccination. A fall in anti-HBs titre below 10 mIU/ml was observed at the follow up in 4/24 (16.7%) of the subjects. In other 5 children (20.8%) anti-HBs titre was found to be just above 10 mIU/ml. This would suggest that a revaccination is indicated and it could be performed at the age of 5-6 years when children enter school. This schedule is simple, effective and money saving since it reduces the cost/benefit ratio and the number of visits for immunisations, and it is expected to improve the compliance for the vaccination.

Duration of the immune response to MMR vaccine in children of two age-different groups.

A combined vaccine against measles, mumps and rubella (MMR) was administered to both a group of children aged 10-12 months simultaneously with booster doses of compulsory diphtheria-tetanus toxoids and oral poliovirus vaccine and a group of children aged 15-24 months who had previously received booster doses of the compulsory vaccines. Apart from one subject belonging to the second group who was non responder and one from the same group who did not seroconvert against the mumps virus alone, 5 to 6 weeks after MMR vaccine administration we found protective levels of antibodies against measles, mumps and rubella viruses in all children. The follow up of both groups at 3 years did not reveal difference between the two groups. Protective levels of serum antibodies against measles and mumps were found in the two groups, although a significant decline of rubella antibodies was shown (p < 0.05). Since the immunogenicity of the vaccines in the two groups did not differ, we recommend that the scientific community reconsider the vaccination schedule until now recommended. In our opinion the MMR vaccine should be administered simultaneously with booster doses of diphtheria-tetanus toxoids and oral poliovirus vaccine at 10-12 months of age because this policy improves parents' compliance, markedly reduces community costs and simplifies routine immunization schedule.

Immune response to simultaneous administration of a combined measles, mumps and rubella vaccine with booster doses of diphtheria-tetanus and poliovirus vaccine.

A combined vaccine against measles (Edmonston-Zagreb 19 strain), mumps (Rubini strain) and rubella (Wistar RA 27/3 strain) was administered to a group of 46 children aged 10-12 months simultaneously with booster doses of compulsory diphtheria-tetanus toxoid and oral poliovirus vaccine. A second group of 53 children aged 15-24 months who had received booster doses of the compulsory vaccines 5 to 12 months before was also vaccinated. The same seroconversion rates (100%) and similar antibody titers for rubella were observed in both groups. The same seroconversion rates for mumps (93%) and similar rates for measles (98 and 94%) were observed in the two groups. Significantly lower antibody titers for measles and mumps were found in the first group, but they were compensated by an earlier protection, a reduction of number of visits for immunization, costs for the community, and improvement in parental compliance. These results confirm that Edmonston-Zagreb 19 and Rubini strains are still immunogenic even when they are combined with Wistar RA 27/3 strain. Moreover, a long term follow-up in order to verify the persistence of protective antibody levels in both groups of children, could suggest that combined measles, mumps and rubella vaccine could be given earlier (at 10-12 months of age), simultaneously with booster doses of diphtheria and tetanus toxoid and of trivalent oral poliovirus vaccine.

Simultaneous administration of HB recombinant vaccine with diphtheria and tetanus toxoid and oral polio vaccine: a pilot study.

An extensive vaccination program to be used in highly endemic areas is the main strategy against the spreading of hepatitis B. The purpose of this study was the evaluation of the immune response to the recombinant HB vaccine administered singly or at the same time as other compulsory vaccines anti-diphtheria, anti-tetanus and oral anti-polio. Evidence was found of the serological efficacy both of HB vaccine and compulsory vaccines with a percentage of seroconversion of 100%. However, the infants who received HB vaccine at birth and at the age of 1 month had titers of antiHBs higher than the infants who received HB vaccine at birth and at 3 months. No difference in antibody levels of compulsory vaccines was observed among the study groups and the controls who received only compulsory vaccines. Our results suggest that HB vaccination must be encouraged and pursued in all newborns.