Rob Stein

Now, the Centers for Disease Control and Prevention defines a "close contact" as spending a total of 15 minutes within 6 feet of an infected person over a 24-hour period.

Coronavirus test results are coming back faster but still taking too long to help fight the pandemic effectively, a national survey shows.

The average wait time for results has dropped to about three days, but that is still too slow to keep infected people from unknowingly spreading the virus, researchers report.

President Trump says he is feeling well, but questions about his health continue to swirl just over a week after his tweet that he'd tested positive for the coronavirus.

Trump's physician said Trump could resume "public engagements" as soon as Saturday. But experts say that may be too soon, both for his own health and the safety of those around him.

Even regular testing is no substitute for routine mask-wearing and social distancing along with quarantining for those who've been exposed to the coronavirus, experts say.

The scientists' work led to a test to protect blood transfusion recipients from hepatitis C and drugs to treat the infection that have saved millions of lives, according to the Nobel Assembly.

President Trump and the first lady have contracted the coronavirus. At 74, Trump could be at risk of developing serious complications from the virus.

Some public health experts hope the growing availability of faster, cheaper tests could lead to a new strategy of widespread testing — one that could finally get the pandemic under control.

The Centers for Disease Control and Prevention reversed its controversial suggestion that people who have been exposed to someone with the virus don't need to be tested if they have no symptoms.

The Trump administration has blocked the Food and Drug Administration from regulating many new tests, raising concerns about the reliability of new coronavirus tests and the FDA's independence.

Many localities require a negative coronavirus test for various activities, such as traveling or visiting an older relative. But finding a test with a quick enough turnaround can be challenging.

During an online forum sponsored by Harvard, Dr. Anthony Fauci discusses how his high-profile position has affected his family personally.

The coronavirus outbreak is getting worse in many parts of the country, and the U.S. will likely need to learn to cope with having the virus be a part of life for many more months.

The National Institutes of Health is giving $248.7 million dollars to seven companies developing new technologies for testing, including use of the revolutionary gene-editing technique CRISPR.

With the coronavirus spreading out of control in many parts of the U.S., some experts say the strategy of testing and tracing can't contain the pandemic until lockdowns bring case numbers down.

The first gene therapy for hemophilia could be approved by the FDA within six months, according to the drugmaker, raising hopes among families. But the drug's price could be $3 million per patient.

Why is the US suffering such a shortage of testing? The Trump administration is promising to perform 100 million tests by September. Is that realistic?

Doctors are using a new antigen test that is a faster method to spot people infected with the coronavirus. It's cheaper and simpler but may be less reliable.

A new NPR/Harvard analysis finds most states' testing efforts still fall far short of what's needed to beat back the pandemic. Find out how your state is doing.