More than half of U.S. states will have to significantly step up their Covid-19 testing to even consider starting to relax stay-at-home orders after May 1, according to a new analysis by Harvard researchers and STAT.

More than half of U.S. states will have to significantly step up their Covid-19 testing to even consider starting to relax stay-at-home orders after May 1, according to a new analysis by Harvard researchers and STAT.