Polio immunization and serological status in children and adolescents in Jamaica (1985)

A survey of immunization status and serological immunity to polio was carried out in 5 parishes in Jamaica in 1985. A sample of 2,506 children and adolescents aged 1-19 years was chosen by selecting clusters of children in enumeration districts (EDs) in each parish from the 1980 Census. Immunization status was verified by examining immunization records. Serological assay for antibodies to Polio Types 1, 2, and 3 was done. A positive neutralization test at dilution of 1:8 was taken as immunity to the polio virus. Of the 1,819 children whose immunization status was confirmed, coverage with 3 or more doses of oral polio vaccine was highest in the 1-4 year age group with 79.7% and lowest in the 15-19-year age group with 37.4%. Of the 2,506 children 81.4%, 94.7% and 72.3% were seropositive for Polio Types 1, 2 and 3 respectively. There was a significant difference in the prevalence of seropositives between individuals with and those without a history of vaccinations. No urban/rural or sex differences were noted. The study indicated a higher level of immunization status than previous surveys and a high level of serological immunity to polio.