Use of killed poliovirus vaccine in a routine immunization program in West Africa

Combined diphtheria-tetanus-pertussis (DTP)-killed poliovirus vaccine was used (along with bacille Calmette-Guérin, measles, yellow fever, and smallpox vaccines) in a routine immunization program in a rural area of Senegal. A control group in a neighboring region received DTP vaccine without poliovirus vaccine. All immunizations were given at two sessions six months apart by a small mobile health team led by a nurse. Six months after the second dose of DTP-polio vaccine, 97.4%, 97.7%, and 90% of subjects two to eight months old at the start had detectable antibody to poliovirus types 1, 2, and 3, respectively. In the control group, 50%, 38%, and 80% of such subjects had antibody to poliovirus types 1, 2, and 3, respectively, acquired by natural infection during the study year. An average of 3.9 cases of paralytic poliomyelitis (range, one to 13) were observed annually at one dispensary in the test region from 1966 through 1979. From 1980 through 1982, since the immunization program has been in effect, only one case has been observed (in a nonimmunized child).