Due to universal administration over years. The polio vaccine is particularly an awful one, with only about 90% effectiveness (matching the covid vaccine) but t

Due to universal administration over years. The polio vaccine is particularly an awful one, with only about 90% effectiveness (matching the covid vaccine) but the ability to cause polio as a side effect. Polio is nearly eradicated because so many people got the vaccine. It only works if everyone does it.