Had an micro teacher a long time ago at community college where 90% of his students were in healthcare career tracks. He told us when we’re hometo eat and roll in the dirt and for the most part only wash our hands after the toilet and before eating / prepping food or anything specifically medical like wound care or putting on contracts. …then at work you wash your hands every time you touch something and before touching your face. Said that was the key to a strong immune system.