To the Editor:April 28, 2021

I had to smile, a bit wryly, reading Rick Mellerup’s account of how variolation (scratching a small amount of dried or fresh pustule material from a less virulent strain of pox into the skin) was roundly denounced by the Boston chest thumpers of the day (“Vaccinations Were Hot Issue All the Way Back to Puritans,” 4/21). The method had been practiced in the Ottoman Empire in the 15th century by women folk healers, probably from Circassia, but was largely unknown to Europe.