There are inexpensive ways of boosting immune systems with supplements, such as zinc, vitimans C and D3, Beta Glucan, and NAC.  But public health officials have not educated the public about the value of supplements in the Covid battle.  The reason is that so-called public health officials are shills for Big Pharma's profits, and Big Pharma regards good immune systems as a hindrence to profits.

There are also two effective, safe, and inexpensive cures for Covid.  One is the combination of hydroxychloroquine (HCQ), azithromycin, and zinc.  The other is the combination of ivermectin, azithromycin, and zinc.  See:  https://www.paulcraigroberts.org/2020/11/23/effective-treatment-and-prevention-is-available-for-covid-19/ 

The use of these known cures has been blocked by public health officials, such as Tony Fauci of the National Institute of Health.  Again, the reason is Big Pharma's profits.  The use of these effective cures negates the profit opportunity of a new vaccine.  

So many have died by denying treatment while we wait for a vaccine that some experts worry will be more dangerous than Covid—https://principia-scientific.com/robert-f-kennedy-jr-covid19-vaccine-should-be-avoided-at-all-cost/ .