Another COVID-19 booster dose could be recommended for older Coloradans as soon as Tuesday, a Colorado health official said Monday afternoon, though federal funding worries may disrupt further distribution plans.

Both Pfizer and Moderna, the makers of two-dose initial vaccines with a third booster, have submitted documents to federal health regulators to receive approval for a second booster, said Heather Roth, the immunization branch chief for the state’s Department of Public Health and Environment. While Moderna requested approval for every adult and Pfizer is seeking approval for those 65 years of age and older, Roth said federal regulators are expected to give approval for a fourth dose to 50-year-olds and above.

If that approval comes this week, the 50-and-up crowd in Colorado will join immunocompromised residents as being recommended to receive another dose.

Roth described the federal action as “kind of an optional recommendation.” The New York Times and Bloomberg News reported that, unlike previous authorizations, the Food and Drug Administration is expected stop short of a full recommendation, meaning the option would be open for those who want it.

Congress has yet to authorize more pandemic funding, meaning that, among other things, officials are signaling that stocks of COVID-19 treatments will be lower than previously. The federal government told the Colorado health department last week that its allotment of monoclonal antibody treatments would be 35% smaller than earlier in March.

Roth said the state has sufficient supplies to continue doling out doses for those currently approved, but she said the state “may run into issues if funding isn’t secured” to help support a new booster recommendation. 

Thus far, officials said last week, the decrease in funding and treatments has coincided with a relative pandemic lull: Cases are near their lowest points in 18 months, and hospitalizations are near their lowest levels since the early days of the crisis two years ago.

Rachel Herlihy, the state’s epidemiologist, told reporters Monday afternoon that this trend was “great news.” She noted that the positivity rate – meaning the percentage of COVID-19 tests that have returned positive over the past week – had ticked up slightly, as had cases overall. Cases have risen elsewhere nationally, as a subvariant of omicron – called BA.2 – has begun to spread. 

Herlihy cautioned that it was too soon to tell if the positivity uptick was a true trend or an aberration. According to the Centers for Disease Control and Prevention, 21% of Colorado’s recent cases have been caused by the subvariant, below the national level of 35%. BA.2 is more transmissible than the primary omicron strain, though it’s not more severe. Officials said last week that they expect BA.2 to account for a larger share of Colorado’s cases going forward but that, given the high levels of immunity here, the subvariant shouldn’t lead to a surge comparable to previous waves.

Bloomberg News contributed to this report.