As COVID cases rise over the winter, health experts are finding that it’s taking longer to figure out if someone is infected.
When COVID-19 antigen tests — also known as rapid tests — first came out, it would take an average of one to two days after symptoms started for someone to test positive.
Now health experts are finding that it’s taking as long as four days after symptoms appear for someone to test positive.
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“People’s immunity is getting better over time,” said Dr. Peter Chin-Hong, an infectious disease expert at the University of California San Francisco. “So it means even a little bit of virus inside of you will be swooped by these immune cells that are just ready to go.”
That accumulated immunity from COVID came came from vaccinations or previous infections.
The problem is: people who initially test negative and then don’t test later may be unknowingly spreading the virus.
It’s always best to be careful around others, according to Chin-Hong.
“I would probably keep a mask on for 48 hours and take another test,” he said. “Or get a PCR test in the beginning if it means a lot to know for sure if you’re positive or not.”
And, if you have any doubts, take another rapid test or go to your doctor for a PCR test — especially if you’re at high-risk and are considering getting a Paxlovid prescription to treat symptoms.
“With Paxlovid, you have to get it within the first five days. But today most people, even in today’s immune cells repertoire, should be able to test positive within five days,” Chin-Hong said.
This comes as a more contagious subvariant, JN.1, may be contributing to the latest jump in COVID cases.
More California counties joined the Center for Disease Control and Prevention’s Medium Level for COVID hospitalizations Friday, including Alameda and Contra Costa Counties.
