SAN FRANCISCO, Calif. (KRON) – If you think there’s a chance you might have COVID-19, there’s a new technique you should be using while testing at home. In addition to swabbing your nose, experts say you should also try swabbing the back of your throat.

It may sound gross depending on the order you do it, but some doctors are now recommending that you swab the back of your throat when using at home tests. This is because that’s actually where the latest omicron variant concentrates in your body.

Plenty of people have heard about some friends or family members getting false negative results with antigen tests, so this is just one more way to get more reliable results.

“I think I found out I had COVID-19 probably by the time I was a week into actually having COVID,” Bhavin Shah told KRON4 News. And he is not alone. 

Many people across the country and right here in the Bay Area have walked around with COVID-19 at some point, unaware that their multiple at-home test results were inaccurate. Thankfully in Shah’s case, he says he proactively quarantined back in May when he first felt symptoms.

“I was feeling symptoms throughout the entire week starting on Monday and I kept on taking home tests and they all came back negative but the symptoms weren’t going away,” he says.

Shah says he took up to seven at-home tests, yet not a single one came back positive. He says it wasn’t until he got a PCR test, that his results revealed he had COVID-19.

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Infectious disease specialist at UCSF, Dr. Peter Chin-Hong says the false negatives can happen more often for those who are vaccinated. “They have a lot of antibodies floating around so when they get exposed to the virus, that might cause a mild infection or asymptomatic infection. The immune system is already revved up from those antibodies floating around from vaccines you’ve gotten. Turns out the at-home tests, antigen tests, require more than 100,000 virus particles to turn positive so you can imagine you start feeling sick earlier than having enough virus to pick up a positive on a test.”

Dr. Chin-Hong says the second biggest reason for possible false negatives has to do with where this latest strain of omicron lives in the body. “It’s really predominately starting out in the large airways and back in the throat before moving up to the nose so with this particular variant it turns out most of the action is happening in the throat,” he said.

For the most accurate test results, Dr. Chin-Hong recommends taking a PCR test once you start feeling symptoms. The next time you do at-home testing, he says you should also swab the back of your throat and test multiple times.

Dr. Chin-Hong says to “combine a sample from your throat and nose, apart from the ick factor, it’s something that’s been espoused by the UK for sometime now.”

While the U.S. hasn’t officially come out and said swab the back of your throat and your nose, Dr. Chin-Hong says there’s nothing scientifically wrong with doing so. He says it will only improve the sensitivity of your at-home tests. Results can still come back false with that method so above all, he recommends taking a PCR test earlier on in infection.