Thread by @newscientist

Do face masks work against the coronavirus and should you wear one? (Thread...) newscienti.st/3aW6jxV

Advice varies between governments and health authorities. The @WHO currently only recommends face masks for people who are coughing or sneezing, or for those who are caring for people who are suspected to have #covid19.

According to a review of 31 published studies, there may be a small benefit to wearing some kind of face covering. They do seem to prevent sick people from spreading the virus, but the evidence is weak and inconsistent.

If medical masks are not available, homemade masks may be worth using. An effective mask fits tightly around the face and filters out virus particles. Vacuum cleaner bags are good at this.

The @CDCgov provides advice for making masks: cdc.gov/coronavirus/20…