Mass Oral (Sabin) Poliomyelitis Vaccination in Czechoslovakia

Extensive epidemiological, virological, and clinical studies have been carried out in Czechoslovakia since 1957, when mass vaccination against poliomyelitis was initiated in this country. At first, following antibody surveys in various regions, Salk-type vaccine was given, and the effectiveness of this procedure was evaluated by means of serological surveys (Skovrinek et al., 1958a(Skovrinek et al., , 1958b;; Zdcek et al., 1960 Zdcek et al., , 1961)). A field trial with oral vaccine was begun in 1958-9, using Sabin's strains of attenuated polioviruses (Skovranek and Zcek, 1959Zcek, , 1960;; Skovrdnek, 1960a Skovrdnek, , 1960b;; Zd,ek et al., 1960 Zd,ek et al., , 1961) ) ; based on the success of this project, a nation-wide oral vaccination campaign was carried out in 1960. Preliminary results of virological and serological studies made in connexion with the administration of live attenuated virus vaccine have been published elsewhere (9kovrdnek, 1961 ; Skovranek and 2Aek, 1961); it is the purpose of the present communication to summarize our recent experiences, with emphasis on serological results using different dosage schedules, and virological surveillance to determine how long attenuated polioviruses persist in communities in which large-scale oral vaccination has been carried out.