If symptoms develop see if he can get the hydroxychloroquine and azithromycin, and a nebulizer with pulmacort, or ivermectin, best to start treatment early if symptoms develop, and not wait until it gets worse. Zinc and vitamin D the best course for now if asymptomatic.
We use it in Brevard county, FL elections, works great. It was 100% accurate in the 2000 election recount as opposed to counties using other methods.