Serological evaluation of poliomyelitis oral and inactivated vaccines in an urban low-income population at Rio de Janeiro, Brazil.

Oral and inactivated poliomyelitis vaccines (OPV and IPV), were given to 160 children two months old, in a low income population at Rio de Janeiro. The vaccination was repeated 2 and 4 months later, always in association with diphtheria, tetanus and pertussis (DPT) vaccine. Blood specimens were collected before vaccination at the time of the third dose of vaccine and later at the time of measles vaccination, when the children were nine months old. The serological response to two doses of IPV showed high titres of antibody in all but one child and 100% conversion after three doses. Although poliomyelitis has been controlled in Brazil by the use of OPV in large mass campaigns, the results obtained with IPV support the possibility of its use in the basic immunization schedule, providing lower costs could be achieved for the inactivated vaccine.