Should you take an at-home COVID test before Thanksgiving gatherings? What experts say

Another holiday season complicated by the COVID-19 pandemic has arrived, except this time we have a line of defense made up of widely available vaccines.

Infection after vaccination is still possible, however, so other coronavirus preventive measures — such as testing — are just as important this Thanksgiving as they were last year, especially as the delta variant continues to spread.

Traditionally, you would go to a pharmacy to complete a PCR test — a molecular test that looks for traces of coronavirus genetic material — and receive your results in a couple days.

Now, federal health officials have authorized several rapid “antigen” tests that you can buy and take at home. Within minutes, these tests can reveal if you are harboring even the tiniest amount of coronavirus by detecting bits of its proteins.

But should you take an at-home COVID-19 test before gathering for Thanksgiving?

Health experts say it’s a good idea, however the tests don’t come without some limitations. They’re hard to find, costly — between about $10 and $40 — and generally less accurate than their PCR cousins.

“Despite its limitations, rapid testing for COVID-19 is a strategy worth considering for holiday gatherings or group activities during which exposure to the virus is possible. Ideally, simplified rapid testing will become readily available at low (or no) cost soon,” Dr. Robert Shmerling, an associate professor of medicine at Harvard Medical School in Boston, wrote in a Harvard blog post.

In October, the White House announced it would invest $1 billion in rapid at-home coronavirus tests in response to high demand and an ongoing shortage.

“So, think about putting rapid COVID testing on your holiday to-do list, and consider offering tests to guests before you sit down for the turkey,” Shmerling added. “It doesn’t take long, and the turkey probably won’t be ready on time anyway.”

When is the best time to take a rapid at-home COVID-19 test?

Because rapid at-home tests may be hard to find this holiday season, experts say the specific brands shouldn’t worry you too much.

“Any of the tests that you can find are way better than not having tests,” Dr. Ashish Jha, dean of the Brown University School of Public Health in Rhode Island, told the Los Angeles Times.

“Rapid tests are a measure of contagiousness, and so you want to test as close as you can of getting together with people,” Jha said. “The ideal situation would be to test on Thursday morning.”

But if you plan on celebrating the holidays over several days with others, Jha suggests testing more than once. For example, right before arriving at your destination and again two days later.

One option, especially if you’re hosting Thanksgiving dinner, is to test each person as soon as they arrive, Shmerling of Harvard suggests. “It might slow the reunion process down a bit, but only for a few minutes.”

Dr. Emily Volk, president of the College of American Pathologists, plans on taking this approach for her own family’s coronavirus-free holiday.

“We will be using rapid tests to doublecheck everybody before we gather together,” Volk, who is planning a dinner with six vaccinated family members, told The Associated Press. “We’ll be doing it as they come in the door.”

Are rapid at-home COVID-19 tests accurate?

Generally, at-home rapid antigen tests will detect higher levels of the coronavirus, meaning a positive test result may reveal a person is very contagious, experts say.

But they do have higher rates of false negatives than the more accurate PCR tests, which are more sensitive and catch lower levels of coronavirus in people, Shmerling said. Still, “a negative result suggests there’s too little virus to infect others, at least at the time of the test.”

Dr. Alok Patel, a pediatric physician at Stanford Children’s Health, told ABC7 at-home COVID-19 antigen tests “are basically looking to see if you have some presence of the virus in your nose.

“That isn’t necessarily going to say you’re going to develop symptomatic COVID-19, you’re going to become seriously ill or you’re going to infect everyone in the room,” Patel said. “But, it is telling you that there is some virus in your nose and it’s a possibility.”

Experts say testing and other preventive measures such as mask wearing and physical distancing are extra important if you’re gathering with unvaccinated, immunocompromised or older people who are more vulnerable to COVID-19.