Ring a ring a roses has been discredited for the bubonic plague. However has anyone considered it for smallpox?
Smallpox produces a rash i.e "ring a roses". It's symptoms are described as "flu like" which involves sneezing "atishoo atishoo". It also had a high mortality rate, especially among the young. "We all fall down"
Edward Jenner vaccinated against smallpox using cowpox. The English version as its second verse "cows in the meadow eating buttercups, atishhoo atishoo, we all jump up."