For instance, if you only get a very faint line, it might be hard to know whether or not that means your results are positive. I know how that feels firsthand. After more than two years of evading ...

Abundant, free, rapid tests, many experts argue, are vitally important for mitigating what we know is fast becoming an endemic virus — Covid-19. But that is easier said than done. Between supply ...

A 2022 study estimates that at-home flu tests have a sensitivity of about 63% if the test is performed within 72 hours of ...