Disease and vaccination in a Wild West counterfactual

If transported to the Wild West, how would Dan survive and help people with smallpox or dysentery?

He would seek smallpox vaccination before exposure and prioritize rehydration for dysentery.

In a hypothetical move to the Wild West, Dan would avoid smallpox exposure until vaccinated. His proposed response to dysentery centers on rehydration, using the water left after boiling rice while healthy people eat the rice itself. A suggestion of filtering water through sand and stones is limited to removing particles. Later recollections contrast a younger participant who missed routine smallpox vaccination with others vaccinated during military service or travel.