The Centers for Disease Control and Prevention now recommends getting Pfizer’s COVID-19 booster shot five months after completing the brand’s initial two-dose vaccination series.

The CDC, which announced its new policy Tuesday, had previously recommended people who received the first two doses of the Pfizer vaccine to wait six months before getting a booster.

The announcement was made a day after the U.S. Food and Drug Administration lowered the wait between Pfizer’s initial vaccine doses and its booster from six months to five.

Tuesday’s announcement was specifically for people who got the Pfizer vaccine, as the CDC still recommends those who received Moderna’s COVID-19 vaccine to wait six months before getting a booster. It recommends two months between an initial dose of the Johnson & Johnson vaccine and a booster shot.

On Tuesday, the CDC also updated its recommendation for “moderately or severely immunocompromised” children between 5 and 11 years old, advising an extra shot of Pfizer’s primary vaccine four weeks after the second jab.

The new developments come amid a surge of COVID-19 cases fueled by the highly transmissible omicron variant of the virus. On Monday, the U.S. reported 1,082,549 new cases to set a single-day record.

“As we have done throughout the pandemic, we will continue to update our recommendations to ensure the best possible protection for the American people,” Dr. Rochelle Walensky, director of the CDC, said Tuesday.

“Following the FDA’s authorizations, today’s recommendations ensure people are able to get a boost of protection in the face of Omicron and increasing cases across the country, and ensure that the most vulnerable children can get an additional dose to optimize protection against COVID-19.

“If you or your children are eligible for a third dose or a booster, please go out and get one as soon as you can.”

More than 200 million people are fully vaccinated against COVID-19 in the U.S., accounting for nearly 63% of the population.

The FDA on Monday also expanded eligibility for booster shots, approving emergency use of the Pfizer booster for kids between 12 and 15 years old.