https://www.nytimes.com/2020/05/11/h...1c1cdf4dbbc721
From the 4th paragraph:
Evidence is mounting that masks — if worn in public places, by everyone — are far more effective at stopping transmission than was previously realized. Across the nation, testing remains wholly inadequate, but home-use nasal swabs and saliva tests are on the way that may provide a clearer picture of where the virus is.