MEASLES, POLIO AND TETANUS TOXOID ANTIBODY-LEVELS IN GAMBIAN CHILDRENAGED 3 TO 4 YEARS FOLLOWING ROUTINE VACCINATION

A nation-wide cross-sectional survey of 816 children 3-4 years old was carried out in The Gambia between September 1990 and July 1991 to ass ess the seroprevalence of antibodies against 3 diseases included in th e expanded programme on immunization: measles, poliomyelitis and tetan us. Among 689 children whose records were available, 94.5% were fully immunized. Measles vaccine was administered to 97% of the children and 91% of these had detectable antibodies at the time of the survey. Ant ibodies against type 1 and type 3 polioviruses, after up to 6 doses of oral polio vaccine, were present in 88.1% and 89.3% of the children r espectively. Ninety-seven percent of the children who had received 4 d oses of diphtheria-pertussis-tetanus vaccine (DPT) and 91% of those wh o received 3 doses had detectable tetanus toroid antibodies at the age of 3-4 years. This study shows that serological responses to EPI vacc ines given in infancy persist at very satisfactory levels throughout e arly childhood.