I heard an audio recording, explaining that the best preventive measures are generally good practices:
1. Frequently drink warm liquids like coffee, tea, soup, or warm water.
2. Gargle with warm water and an antiseptic.
3. Frequently wash yourself, your clothes, and surfaces with soap or detergent.
4. Eat fruits and vegetables.
5. Protect your throat by not smoking, avoiding eating or drinking cold things, and treating sore throats immediately.
Breathing is also good because Covid-19 is a respiratory ailment, so we need our lungs to be robust and fully functional.