Question

The chart gives the number of cases of polio between 1937 and 2011. Polio is an infectious disease that causes paralysis and sometimes death. The polio vaccine was introduced in 1955. What can be concluded about the polio vaccine?

Answer 1

the polio vaccine contains dead and attenuated virus and is called Salk and Sabin .it provides active immunity against the polio virus . it is given orally in form of drops or injected at infancy to make the child resistant to the disease.