How effective was Jonas initial testing of the polio vaccine?

The initial testing of the polio vaccine by Jonas Salk was highly effective. The vaccine was first tested on a group of children in Pittsburgh, Pennsylvania, in 1954. The results of the trial showed that the vaccine was 80-90% effective in preventing paralysis from polio. This level of effectiveness was considered to be a major breakthrough in the fight against polio, which was a devastating disease that had caused paralysis and death in millions of people worldwide.

The success of the Salk vaccine led to a dramatic decrease in the incidence of polio in the United States and other countries. By 1961, only 56 cases of polio were reported in the United States, compared to over 58,000 cases in 1952. The Salk vaccine was also effective in preventing polio in developing countries, where it was often used in mass vaccination campaigns. As a result of these campaigns, polio has been virtually eliminated from most of the world.

The Salk vaccine was a major turning point in the fight against polio. It was the first effective vaccine for the disease, and it paved the way for the eventual eradication of polio.