Jenner's successful use of cowpox virus as a vaccine against the smallpox virus is 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) cowpox and smallpox are antibodies with similar immunizing properties.
D) there are some antigenic determinants common to both pox viruses.
E) cowpox and smallpox are caused by the same virus.

Question

Quizplus · Accepted Answer

Jenner's success was due to the fact that cowpox and smallpox share some common antigenic determinants, which allowed for cross-reactivity and protection against smallpox. This is the principle of immunological memory and cross-reactivity that underlies the effectiveness of vaccines.

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