Omicron BA.5 is now the dominant COVID variant, and it’s spreading faster than previous strains. The test positivity rate in California was approaching 17% for May 12 to July 6, but that’s likely a vast undercount since home testing data is mostly unreported and ungathered.
In the midst of summer travel season, how should you approach testing now, and what does a negative home result really mean?
Omai Garner, director of clinical microbiology for UCLA Health, says home tests are working on new variants, but not in the same way as tests administered at official sites.
“With the new variant … people, especially vaccinated people, were more likely to see false negative home tests early in an infection, that then were turning positive a few days … after symptomatic illnesses started.”
He notes that a PCR test hasn’t shown the same level of false results, so if you feel sick, take a PCR test and it shows negative, then you can be confident that you’re COVID-free at that moment.
“If you don't have PCR availability, we're really suggesting you wait 48 to 72 hours before you test again on a home antigen test. And then if that one is negative, you can have a higher confidence in not having COVID,” he says. “I think the question is: What do you do in the meantime, right? … Have a mask on … because you are possibly contagious with COVID.”
The virus can still spread outdoors too. “Concerts or places where you have a highly condensed population outside, you're still sharing breathing space with a lot of people. … When you're sitting across from somebody and they're eating, there's quite a bit of breath and spit shared across the table. And so being outside may not save you from the person across from you having COVID.”