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 Plus, small unpublished study on T-cell response reports that it is still present six months after Covid infection.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

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

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

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

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