NEW YORK -- So many families gathered this weekend, but COVID-19 didn't hide as Santa Claus was coming to town.
The U.S. is now averaging 198,404 new coronavirus cases each day as of Sunday, the day after Christmas, according to new data from Johns Hopkins University. That's 47% higher than a week ago and the highest such number since Jan. 19.
Those who were exposed to COVID-19 while attending a holiday gathering or visiting loved ones should get tested five to seven days after the day of exposure, said ABC News' contributor Dr. Darien Sutton.
"That's about how much time it takes for the virus to increase in the body and turn a test positive," he said on "Good Morning America" Monday.
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Vaccinated individuals don't need to quarantine after exposure, but Sutton recommends masking during this period of high viral transmission.
People who are not fully vaccinated are at much higher risk for infection and experiencing more severe forms of the illness, so anyone who is unvaccinated and exposed to COVID-19 should quarantine for 14 days, Sutton said.
After exposure, Sutton recommends getting a PCR test, which is more sensitive and more accurate than a rapid antigen test.
Any patients experiencing symptoms, however, should opt for the antigen test, as they are more accurate in the days after infection.
"You can say that if you test positive on an antigen test, you can presume that that's when you're most infectious. It helps to use it before an event. You want to use it as close as possible [to the event] and have an understanding that it can turn positive later on," Sutton said.