BTW, if you want to know all about Covid-19--and how to help your immune system, watch these 2 Youtube Doctors -- They are exceptional. and have the best, up to date info.
Dr. John Campbell (UK based)
https://www.youtube.com/c/Campbellteaching/videos
-- he has load of info--go to past videos. he does daily updates, and covers many current peer reviewed studies.
Like Take 1 Vitamin D3, 5000 IU (means international units). daily.
Take low dose Zinc. (anything under 40mg daily).
Next guy works in LA, at a major hospital with Covid-19 patients. and has multiple Degrees in Health.
Professor Roger Seheult, MD - (VERY good info)
https://www.youtube.com/c/Medcram/videos
Avoid the MSM for covid-19 info mostly. as they don't cover the details these Doctors cover.