Until the 19th century in India, there was a group of selfless scholarly Brahmins whose job was treating people during the Pandemic. They used to travel village to village & vaccinate everyone without ever caring for their personal safety. Their failure rate was just one in a million!
The British banned these Brahmins and their profession in 1861. The banning led to an increase in smallpox epidemics and plague in the 20th century. This is how the traditional health ecosystem was destroyed during the modern colonization era. And such institutions never recovered!
Source: https://twitter.com/BharadwajSpeaks/status/1388074299945365507 and Susantha Goonatilake's “Toward a global science: mining civilizational knowledge” who in turn quotes Dharmapal's citation of Holwell's report