The Centers for Disease Control and Prevention said Wednesday that the standard 14-day coronavirus quarantine can be cut to seven days with a negative test or 10 days without a test.

The isolation period applies to people who have been exposed to someone who tested positive for COVID-19. 

The policy change had been discussed for some time, as scientists have studied the incubation period for the virus. The policy will hasten the return to normal activities by those deemed to be “close contacts” of those infected with the virus, which has infected more than 13.5 million Americans and killed at least 270,000.

While the CDC had said the incubation period for the virus was thought to extend to 14 days, most individuals became infectious and developed symptoms between four and five days after exposure.

However, Dr. Henry Walke, the CDC’s COVID-19 incident manager, still said the 14-day quarantine is the best way reduce the risk of spreading the virus.

It’s not the first time that the CDC has adjusted its guidance for the novel coronavirus as it adjusted to new research. In July the agency shortened, from 14 days to 10, its advice on how long a person should stay in isolation after they first experience COVID symptoms — provided they’re no longer sick.

CDC officials also warned Wednesday against traveling during the upcoming holidays.

“The best thing for Americans to do during the holiday season is to stay at home and not travel,” Walke said.

"Cases are rising, hospitalizations are increasing, deaths are increasing. We need to try to bend the curve, stop this exponential increase."

For those who insist on traveling, the CDC recommends being tested one to three days before, and then quarantining for seven days after traveling while being tested again three to five days after returning home.