it was therefore decided that before carrying out such a campaign , and to provide basic information for its conduct , a survey should be made to determine the degree of natural immunity to poliomyelitis and the amount of poliovirus and other enterovirus infection in the population , and to compare the poliovirus antibody titres of a small group of children who had already received salk vaccine with those in unvaccinated children living in this area of probable high endemicity .
C0032371
poliomyelitis
C0014378
enterovirus infection