Poliomyelitis vaccination in Ibadan, Nigeria, during 1964 with oral vaccine (Sabin strains).

A mass vaccination campaign of children under 3 years old was carried out in Ibadan in late 1964, following a marked increase in the incidence of paralytic poliomyelitis the previous year. Two doses of Sabin-strain attenuated poliomyelitis vaccine were given-the first of type 2 virus and the second of bivalent vaccine containing type 1 and type 3 viruses-with an interval of four weeks between doses. Although serological tests indicated a low antibody response, there was a pronounced and sustained fall in the incidence of the disease.It is concluded that the immunization schedules currently recommended in North America and Europe (namely, three doses at intervals of 4-8 weeks) are not suitable in Ibadan and similar cities in other parts of Africa, where the type of schedule used in this study is preferable. The virtual elimination of the disease from such regions is not at present a practical proposition, but the annual repetition of mass vaccination campaigns should prevent any increases in its incidence.