Can your at-home COVID test detect the omicron variant? What we know so far

More than 500 million at-home COVID-19 tests are set to be distributed to people across the United States, but are they effective at detecting the fast-spreading omicron variant?

The U.S. will purchase the tests and provide them free to Americans who request them through a website, CNN reported. The tests will be available in January by mail.

President Joe Biden announced the plan in a speech Tuesday, Dec. 21. The administration will determine how many tests each household may request, CNN reported.

As the omicron variant spreads rapidly across the nation, supplies of home tests have run short. Walmart and Walgreens, among other stores, are now limiting sales of home tests, Reuters reported. Walgreens will limit purchases to four per customer, while Walmart will allow shoppers to buy up to eight home tests.

Biden also plans to announce that 1,000 military service members will deploy in January and February to assist at hospitals hit by a fresh wave of COVID-19 cases.

More than 73 percent of the new COVID-19 cases in the United States last week were from the omicron variant, the Associated Press reported.

Here’s what you need to know.

What is the omicron variant?

The omicron variant was first reported by researchers in South Africa on Nov. 24 after several doctors noticed symptoms among their patients that differed slightly compared to those caused by the delta variant, the dominant version of the germ spreading globally, McClatchy News reported.

Genetic sequencing revealed the variant sports a large number of mutations unseen in other variants.

Federal health officials confirmed the first omicron case in the U.S. on Dec. 1, in a fully vaccinated California resident who recently returned from South Africa, McClatchy News reported.

Experts are researching numerous questions about the omicron variant, including whether it causes more severe disease than other versions of the coronavirus, the Associated Press reported.

Early data suggests vaccines still protect you against COVID-19 hospitalization and death, no matter the variant involved, but booster shots offer critical protection against infection compared to primary doses.

“All of us have a date with omicron,” Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, told the wire agency. “If you’re going to interact with society, if you’re going to have any type of life, omicron will be something you encounter, and the best way you can encounter this is to be fully vaccinated.”

Do at-home tests detect the omicron variant?

At-home COVID-19 tests appear to be effective at detecting the omicron variant, with some caveats, MedPageToday reported.

It mostly depends on what part of the virus the test detects, said Pablo Penaloza-MacMaster, assistant professor of microbiology-immunology at Northwestern University Feinberg School of Medicine.

While the omicron variant contains a number of mutations, most rapid at-home COVID-19 tests check the nucleocapsid protein, which has fewer mutations, Dr. Michael Mina, chief science officer at a biotech software company, told MedPageToday.

On Tuesday, Dec. 28, the federal Food and Drug Administration announced that rapid antigen tests do detect the omicron variant but may have reduced sensitivity.

“It is important to note that these laboratory data are not a replacement for clinical study evaluations using patient samples with live virus, which are ongoing,” the agency said, noting that research continues.

Abbott, a company that manufactures rapid at-home tests, said in a statement that its tests are effective at detecting the omicron variant.

“While the Omicron variant contains mutations to the spike protein, Abbott’s rapid and molecular tests — antigen and PCR — do not rely on the spike gene to detect the virus,” the company said.

Siemens also announced that its tests are effective at detecting the omicron variant.

But the U.S. Food and Drug Administration warned Dec. 16 that it had found three COVID-19 tests failed to detect the omicron variant, MedTechDive reported.

Diagnostics from Applied DNA Sciences, Meridian Bioscience and Tide Laboratories returned false negatives for patients with the omicron variant, the FDA said.

Penaloza-MacMaster suggested a quick online search can reveal which viral protein a specific at-home rapid test targets. He also noted that even if the omicron variant evades some tests, they may still be effective against other variants.

When should you take a rapid home test?

The timing of a rapid home test will partly determine how reliable the results are, experts say, particularly with the omicron variant.

“There’s a misconception if you’ve been exposed, you should get tested right away,” Susan Butler-Wu, who directs clinical testing for infectious diseases at the University of Southern California, told Business Insider. “There’s absolutely no utility to doing that if you just got exposed because the virus needs time to replicate.”

Instead, isolate and wait three to five days after exposure to test, experts told the publication. That’s when your viral load should be highest, which produces the most accurate results. Then test again 24 to 48 hours later.

“Especially right now, with such high incidence across the country, if you feel any symptoms, assume you have Omicron,” Michael Mina, an epidemiologist and the chief science officer at eMed, told Business Insider.

What are antigen and PCR tests?

PCR tests work by taking a small sample of coronavirus genetic material and replicating it “thousands of times so it can be more easily detected,” McClatchy News reported. They require trained laboratory technicians and special equipment that only some testing facilities have.

Rapid antigen tests, on the other hand, come in pre-made kits with laboratory-produced antibodies that can glue onto proteins sitting on the surface of coronavirus particles in patient samples. Anyone can complete the test, and it can be taken anywhere, offering results within 15 minutes.

This story was originally published December 21, 2021 at 11:44 AM with the headline "Can your at-home COVID test detect the omicron variant? What we know so far."