The U.S. will lift the temporary COVID-19-related travel restrictions imposed on eight southern African countries on December 31, the White House announced in a tweet on Christmas Eve.

“On Dec. 31, @POTUS will lift the temporary travel restrictions on Southern Africa countries. This decision was recommended by @CDCgov,” the tweet by White House spokesman Kevin Munoz read. “The restrictions gave us time to understand Omicron and we know our existing vaccines work against Omicron, [especially] boosted.”

The restrictions, imposed in late November, affected travel from South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi. The restrictions didn’t apply to American citizens or lawful permanent residents, although those individuals were still required to test negative prior to traveling.

The policy came under fire from the World Health Organization, which said it would punish countries for reporting their findings while doing little to slow the spread. Omicron continued to spread rapidly through Europe and the U.S., where it now makes up a majority of new cases.

Health officials were concerned that the new strain, first discovered in South Africa, could set back the fight against the pandemic. Omicron has more mutations than previously detected strains, and there was some fear that it could be more resistant to current vaccines. 

But CBS News chief medical correspondent Dr. Jon LaPook notes that although doctors are seeing a lot of breakthrough infections among those who were fully vaccinated and boosted, they seem to be “doing better in general than…in the past.” Still, he was quick to warn that “you have waning immunity especially against Omicron.” He added that getting a booster will raise immunity “significantly.” 

Major drug manufacturers say early studies show that at least some of the current treatments for COVID-19 appear to be effective in treating Omicron.

Early data from South Africa and the U.K. also suggests patients face a lower risk of hospitalization from Omicron, although it’s still unclear if that’s because the variant is milder than earlier waves or because more people have some immunity from prior infections. It’s not yet known whether the same trend will hold up in the U.S.

Alexander Tin contributed to this report.