An epidemiological analysis was carried out on 898 children, in order to study the immune response to polioviruses 1, 2 and 3 by means of the measurement of neutralising antibodies. Information was obtained from 522 (58.1%) of the children with regard to their vaccinal position by examination of the observations recorded on the individual vaccination certificates. In this subgroup the immune status in relation to number of Sabin type oral vaccine doses was analysed. The analysis demonstrated a high proportion […]