Jenner's successful use of cowpox virus as a vaccine against the smallpox virus was due to the fact that ________.
A) the immune system responds nonspecifically to antigens
B) the cowpox virus made antibodies in response to the presence of smallpox
C) there are some epitopes (antigenic determinants) common to both pox viruses
D) cowpox and smallpox are caused by the same virus

Question

Quizplus · Accepted Answer

Cowpox and smallpox are caused by different viruses, but there are some antigenic determinants that are shared between them. Jenner realized that exposure to cowpox protected against smallpox because the immune system could recognize these shared epitopes and mount a protective response against the smallpox virus.

Jenner's Successful Use of Cowpox Virus as a Vaccine Against