The U.S. health protection agency on Monday released guidance for the first time on activities deemed safe for people fully vaccinated against the coronavirus, giving the OK to indoor meetings in small groups without the need to wear masks.

The recommendations by the Centers for Disease Control and Prevention, however, still call for people, regardless of whether they are vaccinated or not, to wear a mask in public spaces and avoid nonessential travel as well as medium- and large-sized gatherings.

People wait in line to enter the coronavirus (COVID-19) vaccination site at Yankee Stadium on Feb. 5, 2021 in the Bronx borough of New York City. (Getty/Kyodo)

The announcement comes as the administration of U.S. President Joe Biden is ramping up vaccination efforts, with more than 2 million shots administered each day. The United States is the country worst affected by the pandemic in terms of the number of cases and deaths.

"We believe these new recommendations are an important first step in our efforts to resume everyday activities in our communities," CDC Director Rochelle Walensky told a press conference.

People are considered fully vaccinated for COVID-19, the respiratory disease caused by the virus, two weeks after they have received the second shot in a two-dose series, or two weeks after they have received a single-dose vaccine, according to the CDC.

Under the guidelines, indoor gatherings between fully vaccinated people are likely "low risk" and participants do not need to wear masks or physically distance from one another, the CDC said.

As for meetings between fully vaccinated and unvaccinated people, the agency said the level of precaution measures that should be taken depend on whether the unvaccinated individuals are at increased risk of contracting severe COVID-19, such as being of advanced age or having an underlying condition like cancer or diabetes.

For example, fully vaccinated grandparents can meet indoors with their unvaccinated healthy daughter and her healthy children without wearing masks or physical distancing, the CDC said.

The guidance also states vaccinated people do not need to quarantine or submit to a coronavirus test following exposure to someone with COVID-19 as long as they are asymptomatic.

The CDC, meanwhile, took a cautious stance toward travel, which has been partly blamed for the country's widespread pandemic. Walensky also said coronavirus "variants have emerged from international places, and we know that the travel corridor is a place where people are mixing a lot."

"We are really trying to restrain travel at this current period of time, and we're hopeful that our next set of guidance will have more science around what vaccinated people can do, perhaps travel being among them," she said.