The Centers for Disease Control and Prevention said Friday summer camps no longer need to require masks or social distancing if everyone is fully vaccinated, including the campers, in new guidance issued just ahead of the holiday weekend.

The new guidance says masks and social distancing are not required if everyone at the camp is fully vaccinated but said camps with unvaccinated campers or adults, including any camp for kids younger than 12 not yet eligible for the COVID-19 vaccine, should still encourage or require masks indoors.

The new guidance also recommends that even in camps where everyone is fully vaccinated, campers should be assigned to groups that remain together the entire session and mix with other groups as little as possible.

The updated CDC recommendations say people generally don’t need to wear masks outside, unless they are in a crowded setting or coming in close contact with others. Walensky has previously cited unvaccinated kids playing soccer at camp as an example of an activity where close contact and breathing heavily could increase the risk of transmission.

But CDC says camps should still follow state or local health guidance and could choose to continue to require everyone to wear masks if it’s unclear who is and is not fully vaccinated.

Agency health experts said camps should encourage vaccination for everyone over 12 and should still support campers or adults who wish to wear masks.

CDC Director Rochelle Walensky has faced pushback for guidance that called for kids to wear masks outdoors at camp this summer, even though transmission of the virus that causes COVID-19 is considered low risk in outdoor environments. Walensky has defended the guidance saying that many children are not yet vaccinated and that CDC wants to prevent outbreaks at camps that would force them to close.

But Walensky said CDC’s initial guidance aimed to avoid outbreaks that happened last summer at camps like one in Georgia where 260 campers and staff tested positive for COVID-19, forcing them to shut down early.

“My own kids were home from camp last summer, And I want camps to be open this summer,” Walensky said in a hearing on the CDC budget on Wednesday.

“All of our guidance has highlighted, it’s better to be outside than inside. And what I really want in our camp guidance, and we’re working through revising that guidance in the context of vaccination for 12 to 15 year olds, my whole goal is to make sure that camps can remain open and that outbreaks don’t occur,” she said, though didn’t specify any details on when or if masks should be required.

The CDC considers Americans fully vaccinated two weeks after the final dose of COVID-19 vaccine, or two weeks after the single dose of the Johnson & Johnson vaccine.

ABC News’ Cheyenne Haslett contributed to this report.