In the context of providing protection against smallpox, describe (A) the similarities and (B) the differences between variolation and vaccination. (C) Now explain the mechanisms by which immunization with vaccinia virus provides protection against smallp

Question

What will be an ideal response?

Answer 1

A. Variolation and vaccination are both procedures used to confer immunological protection against the smallpox virus, variola. They both use live virus and stimulate humoral and cell-mediated immune responses against the smallpox virus.
B. Variolation, a method used for only a short period in the 18th and 19th centuries because of the risk of developing smallpox, used dried pustules derived from humans exhibiting relatively mild symptoms of smallpox infection. Vaccination, a safer alternative causing only mild infection, used dried pustules from cows infected with cowpox.
C. Vaccinia and variola have some viral surface antigens in common. Some of the antibodies made against cowpox surface antigens during immunization are able to bind to shared surface antigens also expressed on the surface of the smallpox virus. Through neutralization, these anti-cowpox antibodies are able to bind to and prevent the entry of smallpox into host cells if the host is infected naturally with the smallpox virus.