Pedia News

Vaccination Produces Acquired Memory


Vaccination Produces Acquired Memory
In 1796, Edward Jenner carried out the remarkable clinical experiment that marks the beginning of immunology as a systematic subject. Noting the pretty pox‐free skin of the milk­ maids, he reasoned that deliberate exposure to the pox virus of the cow, which is not virulent for the human, might confer protection against the related human smallpox organism with which it has some antigenic similarity. 

Accordingly, he inoculated a small boy with cowpox and was delighted and presumably breathed a sigh of relief to observe that the boy was now protected against a subsequent exposure to smallpox (what would today’s ethical committees have said about that?!). By injecting a harmless form of a disease organism, Jenner had utilized the specificity and memory of the acquired immune response to lay the foundations for modern vaccination (Latin vacca, cow).

The strategy is to prepare a nonpathogenic form of the infectious organism or its toxins that still substantially retains the antigens responsible for establishing memory cells and protective immunity (Figure 2.12). This procedure can be done by using killed or live attenuated organisms, purified microbial components or chemically modified antigens.