As an RN I have been saying this from day one.
Hydration
Fresh air and sunshine ( Vit. D)
Unmask
Exercise
Reduce stress
Healthy diet ( no soda, no high Fructose corn syrup, no GMO)
Zinc ( slows replication of any virus)
Quercetin ( improves oxygenation to the cells and reduces fress radicals that injures cells)
All thes things BOOST the immune response to all kinds of viruses. Exercise and healthy diets reduce chance of diabetes which is a major risk factor for illness.