Vaccination of infants in their first year of life with split inactivated measles vaccine incorporated in a diphtheria-pertussis-tetanus-polio (inactivated) vaccine (DPTP-M), compared with live measles vaccination

Abstract

A study was carried out to evaluate the clinical reactions and immunological response produced in children to three measles vaccines, two of which were inactivated (KV) and the third one live vaccine (LV). The inactivated vaccine was a split vaccine prepared by Tweenether treatment. The vaccines were given in three different schedules to 1200 children in their first year of life. The two inactivated measles vaccines, produced respectively by the Behringwerke AG and the Rijks Instituut voor de Volksgezondheid, were incorporated along with diphtheria-pertussis-tetanus- and inactivated polio vaccine into a quintuple vaccine (DPTP-M). The live measles vaccine which was prepared from a further attenuated strain (Attenuvax), was given separately. DPTP-M did not elicit more clinical reactions, general nor local, than DPTP. The reactogenicity of LV was only manifested by a rash in 7% of the vaccinees. The rash did not occur, however, when DPTP-M was given before LV. Atypical measles was not observed in children who had first received DPTP-M vaccine followed by LV, nor in those who were naturally infected with measles after vaccination with DPTP-M vaccine. The children who were vaccinated with three doses of DPTP-M vaccine in the first year of life showed a protection against a natural infection in the second half year. When a fourth (booster) dose of DPTP-M was administered at the age of 12 months, the mean HI antibody titers were similar to those found after one dose of live vaccine. The highest mean measles antibody titers were found in the two subgroups of children vaccinated with LV 6 months after the third dose of DPTP-M. However, 1 year after the last injection of measles vaccine, the antibody titers as well as the percentage of seropositives had declined notably in the four groups of children who had received DPTP-M. Lower titers were observed also in the two subgroups of children who received three doses of KV and one dose of LV. On the other hand the mean antibody titer as a result of live vaccine administration was higher 1 year after the vaccination than at the age of 12 months.