New York’s governor threatened to fine hospitals if they don’t use their allotment of COVID-19 vaccine fast enough. His South Carolina counterpart warned health care workers they have until...

As dozens of countries blocked the flow of people and goods from Britain to avoid a new and more contagious strain of coronavirus, scientists raced to understand how it emerged and the scope of its threat. Here...

Very little is known about how to properly reuse medical masks to fight infectious diseases. No method is confirmed to work. Still, in a report to doctors, which has yet to be peer reviewed, some researchers...