"The Temple of Vaccinia".

Edward Jenner's laboratory/shed
where he demonstrated and proved (1796)
that inoculation with the blister-pus of cowpox
'vaccinated' successfully against smallpox.

For at least hundreds of years before that,
within the Turkish Empire
smallpox pus was used with considerable risk
and mixed results. In the 18th century 
observations on the link between cowpox
and subsequent smallpox immunity had been made.