ABSTRACT
Antibodies have only been understood to be protein molecules in the last few decades, but they have been used for much longer. In 1796, Edward Jenner elicited an immune reaction to an attenuated viral antigen that subsequently protected the organism from a closely related antigen.1 He was the rst to perform such a vaccination under controlled conditions, but the use of viral material to provide immunity from future infections, variolation, or inoculation appears to date from many centuries, if not millennia, earlier in China.2
