DENVER (KDVR) — Coloradans can now choose to get a new COVID-19 booster shot after it passed the final hurdle last week authorizing its use in adults and children aged 12 and older, depending on the brand.

Until now, COVID vaccines have only targeted the original strain of the virus, but the Food and Drug Administration granted authorization to Pfizer and Moderna bivalent shots, which combine the original RNA-targeting mixture and a new formula that targets the omicron BA.4 and BA.5 subvariants. A Centers for Disease Control and Prevention panel gave the final recommendation with a vote of 13-1.

The newly-authorized bivalent shots come during a time when the number of Coloradans getting vaccinated for COVID-19 has hit an all-time low.

Pfizer omicron doses are available to Coloradans 12 years and older, while the Moderna version of the bivalent shot is only available to adults 18 and older. Under Colorado’s vaccine finder, doses mainly appear to be available through the state’s fleet of mobile vaccine clinics when looking at Denver metro zip codes. Appointments are available as soon as Tuesday to get the new shot.

A spokesperson for the Colorado Department of Public Health and Environment said the roughly 300,000 doses the state is receiving from the federal government are already in the state, or in transit with an arrival date “no later than Thursday.”

Health officials want to remind the public that the new bivalent shots are not a replacement to the original vaccine, and are considered booster shots. The formal recommendation is to wait at least two months after receiving your last dose or booster before taking the bivalent shot.

You can learn more about the different strategies the state is using to make these shots available here.