Data on the number of cases for these diseases from the pre-vaccine era is hard to come by, and even the case counts are ...

This similar virus is cowpox. The cow to the left has been intentionally infected with cowpox virus. The fluid that you collect from virus-caused pustules on the cow's udder contains many copies ...

Over 200 years after the first successful vaccine was created by an English physician, who discovered that inoculation with the cowpox virus protected against smallpox, vaccines remain one of the ...

Picture this: a world where a highly contagious virus called variola wreaked havoc ... in the late 18th century by using material from cowpox to protect against smallpox. This groundbreaking ...

Armed with the knowledge that milkmaids who had been exposed to cowpox, a relatively mild affliction ... the body against some kind of pathogen—a virus or bacteria or some other agent that ...