Response of children to a single dose of oral or inactivated polio vaccine.

Approximately 200 children aged 8, 12 and 16 years with poliovirus neutralising antibody titres of less than 1/45 to at least one type were given a single dose of oral or inactivated polio vaccine. Almost all children given IPV responded with high levels of neutralising antibody to all 3 types. The response to the oral vaccine was less dramatic. The relationship between pre-existing antibody and the further response and the implications for susceptibility to reinfection will be discussed.