In this situation ,it's better to protect our immune system than investigating on virus or fungus and bombarding our body with medications Always best way of prevention is reducing contact with infected person and Immediate self isolation

Hand washing at frequent intervals even when they aren't visibly dirty Social distancing Double masking Avoid touching nose/mouth as much as possible Healthy protein rich diet Plenty of fruits Adequate hydration

In simple words, Prevent (atleast minimise) virus to reach your nose or eyes. Everybody knows it now how to do it , right! Make your immune system stronger so that even if it invades you are ready to fight and prevent it from causing the disease. For that take good n healthy food supplement it with vitamins (C,D,B) Regular exercise and meditation also

Follow covid protocols.. that itself is main protection. Social distancing, good mask, hand sanitizing. If you follow this you will get protected from covid. And also avoid stepping outside the house unnecessary.