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Rapid COVID-19 tests could bring reassurance for 2021 holiday gatherings, experts say

As the 2021 holiday season quickly approaches, many are looking forward to gathering with family and close friends to celebrate together once again.

This year marks the second pandemic holiday. And while vaccines are now widely available, there are still questions and decisions to make regarding the risk level of attending holiday parties.

Experts say we now know a lot more about testing for COVID-19 than at this time in 2020, and at-home rapid tests could help make a family’s Thanksgiving or Christmas gathering safer when combined with vaccination. 

RELATED: Vaccinated families can ‘feel good’ about holiday gatherings, Fauci says

How do at-home rapid COVID-19 tests work?

At-home test kits for COVID-19, while not as accurate as the PCR tests done in hospitals and test sites, can still add a layer of safety and reassurance by providing on-the-spot results. Rapid testing can have results back within minutes instead of days. 

The U.S. Food and Drug Administration has granted an emergency use authorization to two kinds of rapid tests: molecular and antigen. Most rapid tests available are antigen tests, which detect small bits of viral protein using similar technology to what is used in a pregnancy test, according to Dr. Robert Shmerling, a senior faculty editor with Harvard Health

"And while these tests have a higher rate of false negatives than a PCR test, getting a negative result strongly suggests you aren’t contagious. Even if you are infected, a negative result suggests there’s too little virus to infect others, at least at the time of the test," Shmerling says in a Harvard Health post. 

As a result, experts say rapid COVID-19 tests could be used as a way to screen everyone coming over for Thanksgiving dinner or other holiday parties. Adults and teenagers can test themselves — and an adult can test a child as young as 2. 

Many companies selling such tests offer detailed instructions and how-to videos online. Most tests require swabbing about a half-inch inside both nostrils for a certain period of time, so it may tickle but doesn't hurt. The sample is then applied to a test strip or cartridge, and the results often show a colored line to signify positive or negative.

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FILE - A health worker handles COVID-19 rapid tests at a testing site in Oakland, Calif., on April 29, 2021. (Jane Tyska/Digital First Media/East Bay Times via Getty Images)

"If a visiting friend or family member tests positive, they should leave along with anyone else they might have already exposed. The next step for them would to be to quarantine while waiting for results from a PCR test," Shmerling writes. 

How accurate are at-home rapid COVID-19 tests?

At-home COVID-19 tests will miss some infections and in rare cases mistakenly indicate an infection. One popular test misses around 15 out of 100 infections, which is commonly referred to as a "false negative," and gives a false positive result in about 1 in 100 people who aren’t infected.

A false positive recently played out during a live episode of "The View." Co-hosts Sunny Hostin and Ana Navarro, who were about to interview Vice President Kamala Harris, had to exit the stage during the broadcast due to a positive COVID-19 test. But they later said their results turned out to be false positives.

The FDA has given emergency use authorization to nearly 40 different antigen tests. Overall, antigen test sensitivity varies depending on the time in the course of a person’s infection but it’s generally "moderate-to-high" at times of peak viral load, the U.S. Centers for Disease Control and Prevention says.

Where to buy, cost of at-home rapid COVID-19 tests

Test shortages were widely reported during the last COVID-19 surge, but new options have recently hit the market and major manufacturers such as Abbott Laboratories have ramped up production.

Testing kits are now available at drugstores without a prescription, and a box with two tests typically costs about $25. Swabs, testing solution and instructions are all included.

Several antigen tests, such as QuickVue and Abbott’s BinaxNOW, can be purchased as a multi-pack at local drugstores. Others, like BD Veritor, are available on Amazon

Among approved home molecular tests, the Lucira CHECK-IT kit is available on Amazon at $89 per test. 

Staying safe for the 2021 holiday season 

Despite its limitations, Shmerling calls rapid testing for COVID-19 "a strategy worth considering for holiday gatherings or group activities" where exposure to the virus is possible. 

The U.S. Centers for Disease Control and Prevention offers other tips on ways to enjoy the holidays safely, and vaccination still remains the best way to protect against COVID-19.

This story was reported from Cincinnati. The Associated Press contributed.