A comprehensive investigation of immunity to poliomyelitis in a developing country.
A comprehensive nationwide surveillance program of serologic immunity of two-year-old black children, combined with evaluation of vaccine quality and distribution, was carried out in South Africa during 1983-1984. Sera were randomly collected from urban and rural groups and cluster samples collected from the semi-urban group. The sample represented 0.23% of the total target population. Satisfactory levels of immunity were found in the urban (80%) and semi-urban (71%) groups but a disquietingly low level was found for the rural group (59%). Individual districts in the rural group could be singled out for directed cluster sampling at a later stage. History and documentation of immunization corresponded well to serologic findings and revealed also a fairly substantial level of natural immunization among individuals who, on history, had received no vaccine. Some 95% of random samples of vaccine recalled from the field showed satisfactory levels of potency. An immunity surveillance program such as this is ideally suited and highly cost-effective for developing countries with incomplete immunization to prevent large-scale buildup of immunity deficit. The technique, however, is too insensitive to detect localized community immunity defects.
D000914:Antibodies, Viral / Q000276:immunology / Q000302:isolation & purification*; D002675:Child, Preschool; D003625:Data Collection; D003906:Developing Countries; D004812:Epidemiologic Methods; D006801:Humans; D009500:Neutralization Tests; D011051:Poliomyelitis / Q000276:immunology*; D017955:Poliovirus / Q000276:immunology; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage*; D011897:Random Allocation; D012424:Rural Population; D013019:South Africa; D014505:Urban Population
D000914:Antibodies, Viral; D011054:Poliovirus Vaccine, Inactivated