Answer:
it was only 90 percent effective
Explanation:
In 1954 a massive controlled field trial was launched, sponsored by the National Foundation for Infantile Paralysis. Almost two million U.S. children between the ages of six and nine participated. In some areas of the country half of these “Polio Pioneers” received the vaccine, while half received a placebo. In other areas of the country children who did not receive any vaccine were carefully observed. On April 12, 1955, Thomas Francis, Salk’s mentor and the director of the trial, reported that the vaccine was safe, potent, and 90% effective in protecting against paralytic poliomyelitis.
The reason Dr. Salk approach to developing a vaccine for polio considered unconventional and not fully accepted by fellow virology was because it was fully afficetive. This means the over percent that may of not worked could've been harmful for the person getting that pacific vaccination. This could cause death or worse. Another reason is because if people were to spend money on an vaccination that didn't help them and could've caused death, that would lead to a shutdown with the health center.
