The dominant variant currently has a shorter incubation period — which means if you go to a packed bar on a Friday night and don’t have symptoms by Monday, it’s unlikely you have the virus, Dr. Chin-Hong said. If you still don’t have symptoms by Wednesday, you’re probably in the clear, he said, although you should take a test to confirm.
However, it is still possible to have an asymptomatic case of Covid — and as more people build up immunity to the virus through vaccination and prior infection, asymptomatic, or very mild, cases will be more common, said Dr. Céline Gounder, an infectious disease specialist and senior fellow and editor at large for public health at Kaiser Health News. Even if you do not have symptoms, you can still spread the virus, she said, which makes it important to test right before gathering with a vulnerable person.
“If you’re going to sit down with Grandma for Thanksgiving dinner, I would test immediately before,” she said.
If you do feel sick, stay home — even if you’re negative on a rapid test. “Anyone who isn’t feeling well should stay home,” Dr. Ratner said, “because the tests aren’t perfect.”
Test wisely.
The question isn’t whether or not to test before a family gathering; it’s when to test, and how many times.
Experts differ on the exact timing and combination of tests you should take, but for the most accurate measure of whether or not you’re contagious before an event, take an at-home rapid test right before. “You can just have a little testing party outside, where everyone says, ‘OK, now we’re good, we’re negative, we can go in and see Mom,’” said Stuart Ray, an infectious diseases specialist at Johns Hopkins University School of Medicine. You should also take a rapid test the day before, he advised.
“Rapid tests are very good, but they’re not perfect,” Dr. Pritchett said. P.C.R. tests are more sensitive, but it can take several days to get the results back, she said, and so a five-day-old snapshot of your infection status won’t be helpful in determining if you’re contagious at the moment. If you can get a quick-turnaround P.C.R., that can boost your confidence that you’re negative; if not, take at least two rapid tests, 12 to 24 hours apart. (If you have had Covid in the last two to three months, though, P.C.R.s can stay positive beyond the point at which you’re contagious, Dr. Ratner said, so you should rely on rapid tests.)
