A STUDY OF POLIOMYELITIS RELATED SERO-IMM UNITY IN A SELECTED SAMPLE OF THE FRENCH POPULATION

Today, France is one of the nations which has eradicated paralytic pol iomyelitis. The aim of this study is to give basic data on polio immun ity in the French population. A seroepidemiological study was made on samples collected in 1991 from 300 patients, 150 males and 150 females , 6-80 years of age, and randomly chosen in the Center and West of Fra nce. Antibodies were submitted to neutralization tests in tissue-cultu re microplates. Vaccine (wild and three seed strains) were tal;en into consideration. The prevalence of serum antibodies in random samples w ere assessed in relation to age (vaccination history unknown). A sizea ble proportion (12-44 %) of subjects 50-80 years of age disturbingly s howed a lack of identifiable type 2 and type 3 antibodies, This high p ercentage was especially true for type 3 vaccine strain antibodies. Ap parently, the threshold for general protection could be affected in el derly people. This data should show people how important it is to stri ctly follow recommended vaccination programs and to keep the populatio n under observation for seroconversion and persistence of antibodies a s well as to check environment for poliovirus circulation. This is the only way to eradicate wild poliovirus.