Tried, tested, and vaccinated? Vaccines are the focus of this month's National Science Agenda. In the late 18th century, physician Edward Jenner discovered that milkmaids rarely got smallpox because they instead got cowpox. He then hypothesised that by infecting someone with cowpox, they would be protected from smallpox in the future — and it worked! Jenner named his solution vaccination, after vacca, the Latin word for cow. Funnily enough, Herman, the world's first genetically-engineered bull from Leiden, later also aided in developing the Jansen and Janssen coronavirus vaccine. How about that?