The authors present quantitative data on poliomyelites antibodies detected following vaccincition with trivalent oral vaccine (Table I) . The geometrical mean titer increased after a third dose of vaccine but wild virus infections mlght have been involved also in antibody production besider the vaccinal strains. Coxsackie B and ECHO, vírus types 1. 9. 11. 16, 19 and 30 antibodies have been titrated in the pre-vaccinal blood (Table 2). The authors emphasize the lack of previous data about enterovirus infections in the studied area.