maybe I am missing something here. Most of us follow a lot of medical and scientific advice in our life: eat healthy food (sometimes), take prescribed medicines, brush teeth, fix cavities, wash our hands when a nurse asks us to, etc. You yourself just stated that you avoid people with strep.
How is the covid situation different? what is wrong with suggesting that people use ventilation to decrease sickness going around. Gemora is full of medical advice of such type, including effects of air. Are all amoraim eruv rav!? Probably there is some assumptions that you apply to covid that do not apply to other cases, but I am not sure what is it.