The Salk vaccine field trials were done only in school districts selected by the Public Health Service in consultation with local officials. In these areas, there were about 3 million children in grades 1-3; there were about 11 million children in these grades 1-3 in the whole US. In the experimental areas, the incidence of polio was about 25% higher than in the rest of the country. Did the Salk vaccine field trials cause children to get polio instead of preventing it? Answer yes or no, and explain briefly.
No, Salk vaccine prevented the children from getting polio.
Explanation:
The result was announced in 1955, there was a good statistical evidence the Jonas Salk's vaccine was 80%-90% effective in preventing paralytic poliomyelitis.
