The rollout of the new COVID-19 booster in Maryland remains slow.

In the 50 days it has been in circulation, the bivalent booster has been administered far less frequently in the state than the original booster was over the same time frame last year.

The new booster was originally approved by the Federal Drug Administration (FDA) on Aug. 31, 2022, and was recommended by the Centers for Disease Control and Prevention the next day. The CDC expanded use of the shot to children ages 5-11 on Oct. 12.

As of Thursday, the shot has been administered 600,560 times in the state, according to data from the Maryland Department of Health.

The original booster was approved by the FDA for certain populations on Sept. 22, 2021 and endorsed by the CDC two days later. In the 50 days following the CDC endorsement, 719,478 Marylanders received the original COVID booster, according to the CDC.

Two-thirds of the bivalent boosters administered have gone to individuals age 50 and older, with the largest concentration being in the 60 to 69-year-old age group, according to the state health department.

On a national level, the data show Maryland is indicative of a greater trend of people who are not receiving the second and subsequent boosters. According to figures from the CDC, 111.3 million Americans have received at least one booster, while only 19.4 million have received the new bivalent booster.

In total, more than 2.6 million Marylanders received a first (monovalent) booster, according to the state health department. More than 4.8 million Marylanders completed a primary series of the vaccine, which means either both doses of a two-dose series or one dose of a single series, like the Johnson & Johnson vaccine.