Smallpox<span> 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 </span>cowpox<span> did not later catch </span>smallpox<span> by showing that inoculated</span>cowpox<span> protected against inoculated </span>smallpox<span>.</span>
they generally don't know what's going on, and half of the time they don't know what's wrong with them and once they do know what's wrong, they don't even know what to do to treat it.
