Americans are now eligible for a third order of free rapid at-home coronavirus tests shipped through the Postal Service. The move doubled the total number of tests the program has made available to each household to 16.
The tests are authorized by the Food and Drug Administration and available on the federal website covidtests.gov (or call 800-232-0233).
Here’s what you need to know about the tests:
They work and you should get them
“The short message is that these tests that have gone through scrutiny by the FDA and are out on the market — they do work,” said Nathaniel Hafer, an assistant professor of molecular medicine at UMass Chan Medical School. “This is a great opportunity for people to take advantage and get some more free tests to provide their families and themselves with that piece of mind.”
Hafer said that while questions were raised early in the Omicron surge about whether the tests were effective at detecting Omicron subvariants like BA.2.12.1, which is currently spreading through Massachusetts, research suggests that “the tests are more robust and we don’t have the concern that they’re not going to work.”
The tests can help you - and those around you
Officials recommend using the tests when you have COVID-19 symptoms or five days after you’ve had close-contact exposure to someone who has COVID-19.
They also recommend that people take the tests to keep from spreading the virus to others.
“You can test yourself before going to a large gathering, before you go visit someone vulnerable,” Dr. Ashish Jha, the White House COVID-19 response coordinator said at a briefing Wednesday.
Take two (or more) to be sure
Hafer recommended taking more than one test because sometimes people take the test before the virus is detectable.
“Many of the tests are designed for an individual to take two tests 24 to 36 hours apart. That’s really the best way to get the best performance out of your test,” said Hafer, who is part of a team that has been studying the performance of the rapid tests and the gold standard PCR tests over the past two years. “You should take them serially, one after the other.”
The reason, he said, is that early in the infection the viral load may just have not built up enough. “During the course of a typical person’s infection, they’re going to get infected and the virus is going to build up in the body. Because a PCR test can amplify genetic material, it can detect vanishingly small amounts. In contrast, the antigen test doesn’t have an amplification step, so it’s going to have a more limited ability to detect a small amount of viral protein.”
Dr. Celine Gounder, a senior fellow and editor-at-large for public health at Kaiser Health News, told NPR, “There’s usually a day or two delay between when you might test positive on a PCR versus when you might test positive on one of these at-home rapid antigen tests. ... But they do work to pick up an infection, and they should be used frequently.”
Sometimes, more than two tests might be in order, experts said.
Phyllis Kanki, a professor at the Harvard T.H. Chan School of Public Health who has studied the accuracy of rapid at-home tests, said if you have COVID-19 symptoms, “you should rapid test. And if you’re negative, you should test again the next day.” If the test is negative and your symptoms persist, try more rapid tests, she said, or consider a PCR test.
The CDC says negative rapid at-home tests don’t rule out COVID-19 infections and recommends checking in with your health care provider if you have any questions, especially if your symptoms worsen.
Your health insurance can get you even more tests
In addition to getting free rapid at-home tests in the mail, people can also get them at the store. And those tests are supposed to be covered by health insurance. As of Jan. 15, insurance companies and group health plans have been required to cover the cost of rapid at-home tests.
GBH News reported earlier this month that, in a little-noticed development, most Massachusetts residents can simply show their insurance cards to get free tests at pharmacies, including those in CVS and Walgreens. State officials also told GBH that the tests should also be available for free at pharmacies for people with coverage through MassHealth.
Jeremiah Manion and Kay Lazar of the Globe staff contributed to this report. Material from Globe wire services was used in this report.
Martin Finucane can be reached at firstname.lastname@example.org.