Clinical trial of concentrated inactivated polio vaccine in a simplified immunization program.

The aims of the trial were: 1) to verify the effectiveness of injectable polio vaccine (inactivated) combined with concentrated diphtheria and tetanus toxoid, in one or two injections given at an interval of 6 months; 2) to compare the killed polio vaccine with the oral vaccine which is recommended in the Ivory Coast program: 4 doses in 15 months. The effectiveness of the immunizations is judged by the serum antibody levels 8 to 12 weeks following immunization. The comparative study of 2 inactivated polio vaccines A and C with live oral vaccine showed the superiority of inactivated vaccine, which resulted in good seroconversion after a single dose. The increase in the serologic response is proportional to the antigenic mass since it appears that the concentration of vaccine C is double that of A.