The new and improved triple-layer face mask! You do not have to throw out your old one. It still works. Plus, small unpublished study on T-cell response reports that it is still present six months after Covid infection.

Medical Mythbusting Commentary for November 4, 2020

Study Finds Which Homemade Face Masks Are The Most Effective And Breathable

T-cell response ‘lasts six months after Covid infection’

Ability of fabric face mask materials to filter ultrafine particles at coughing velocity