Every American traveling abroad needs to take an antigen test to return to the United States. But the start of the trip is often even more cumbersome, as many other countries (nearly every one I have ...

(CNN) -- One is widespread but has key shortages across its supply chain. One remains questionably reliable and is only helpful after the fact. And one is still early in development -- but could speed ...

At first blush, you might reasonably dismiss the rapid, saliva-based antigen assay for coronavirus. What possible purpose can a test serve in a pandemic if it misses, say, 30 of every 100 infections ...