DENVER (KDVR) — As Colorado rolls out new COVID-19 booster shots that target highly-contagious omicron subvariants, the state is giving guidance on what providers should do with the old booster doses.

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.

According to the state health department’s website, “the previously approved vaccines made by Pfizer and Moderna are no longer authorized as booster doses for people aged 12 years and older.”

A spokesperson for the Colorado Department of Public Health and Environment said providers are now being instructed only to use those for the “primary series of vaccination for people 12 years of age and older.”

“Providers have been advised to adjust their inventories of primary series vaccines so that there is as little waste of vaccine as possible,” the spokesperson said.

Health officials want to remind the public that the new bivalent shots are not a replacement for 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. You can find a clinic with the new bivalent booster near you here.