People who are fully vaccinated against COVID-19 can travel freely in the U.S., as long as they remain masked on planes, buses and trains, the Centers for Disease Control and Prevention announced Friday.
It is unclear how much impact the new guidance will have. People are already traveling and making decisions on their own. American Airlines reported Monday that the company's bookings have jumped to 90 percent of what they were before the pandemic.
The new guidance means that "fully vaccinated grandparents can fly to visit their healthy grandkids without getting a COVID-19 test, or self-quarantining, provided they follow the other recommended prevention measures," CDC director Dr. Rochelle Walensky said Friday during a news briefing.
Still, the number of COVID-19 cases continues to rise. The current seven-day average of new cases is slightly above 62,000 cases per day.
While fully vaccinated people may travel at low risk, Walensky said, "CDC is not recommending travel at this time due to the rising number of cases."
It is expected that the U.S. will surpass 100 million people who have received at least one dose of vaccine Friday. More than 56 million Americans are fully vaccinated, according to the CDC.
A person is considered fully vaccinated two weeks after their last dose of COVID-19 vaccine. That gives the body enough time to build antibodies against the virus.
This latest guidance offers another step toward resuming normal activity for those who have received both doses of the Pfizer-BioNTech or Moderna shots or one shot of the single-dose vaccine from Johnson & Johnson.
The CDC said COVID-19 tests are no longer required for fully vaccinated people before or after a trip within the U.S., and there is no need for them to self-quarantine. The guidance doesn’t mention whether people need proof of vaccination to travel, though no U.S. airlines currently require such documentation.
The same rules apply to vaccinated people traveling internationally, with some exceptions. Some destination countries may require a negative COVID-19 test for entry. And the CDC recommends people test negative before coming back to the U.S.
And mitigation measures remain even for vaccinated travelers: wear masks, avoid large crowds and wash hands frequently.
Indeed, all U.S. airlines still require passengers to wear masks.
"Taking prevention measures to stop the spread of COVID-19 is the path out of this pandemic," Walensky said.
The CDC has been slowly offering guidance on what people can do once fully vaccinated. In early March, the agency said they may safely gather with small groups from other households without wearing masks or physically distancing, even if those people have not yet had their shots.
This story first appeared on NBCNews.com.