Smallpox vaccine Smallpox vaccine Smallpox vaccine, the first successful vaccine to be developed, was introduced by Edward Jenner in 1796. He followed up his observation that milkmaids who had previously caught cowpox did not later catch smallpox by showing that inoculated cowpox protected against inoculated smallpox. Dryvax is a freeze-dried calf lymph smallpox vaccine. It is the world's oldest smallpox vaccine, created in the late 19th century by American Home Products, a predecessor of Wyeth. By the 1940s, Wyeth was the leading US manufacturer of the vaccine and the only manufacturer by the 1960s. After world health authorities declared smallpox had been
History of HIV/AIDS the necessity to supply workers and because firearms became more widely available. The colonial authorities also gave many vaccinations against smallpox, and injections, of which many would be made without sterilising the equipment between uses (unsafe or unsterile injections). Chitnis "et al." proposed that both these parenteral risks and the prostitution associated with forced labor camps could have caused serial transmission (or serial passage) of SIV between humans (see discussion of this in the next section). In addition, they proposed that the conditions of extreme stress associated with forced labor could depress the immune system of workers, therefore prolonging the