Colorado is still steadily extricating itself from the omicron wave, state health officials said Thursday, with counties across the metro unwinding mask orders and a new subvariant yet to make serious inroads into the state.

Cases, positivity and hospitalization rates have still yet to recover from their pre-omicron levels, let alone from the late summer, before delta began to drive them upward. But all have declined significantly since mid-January, and state leaders reiterated their optimism that the downturn will continue and will hopefully herald a period of relative pandemic calm for Colorado.

“Right now, I think things are looking promising,” state epidemiologist Rachel Herlihy told reporters Thursday.

Denver mask order expires Friday; Jefferson County to end its school, indoor requirements Feb. 18

State experts projected late last month that roughly 80% of the state would be immune to omicron – the dominant, highly transmissible variant – by the middle of February. As of Thursday afternoon, the seven-day average positivity rate had dropped to below 16%, its lowest point since Dec. 28. The state has averaged 4,438 new cases each day over the past week, also the lowest since late December.

The downward trajectory could be complicated by a new variant or subvariant, Herlihy and the modelers warned. An omicron subvariant has already been identified in Colorado and elsewhere in the United States and world. But its confirmed presence here is still small: Herlihy said three cases of the subvariant have been identified and that it has also been identified in wastewater in Boulder County.

The subvariant has been outcompeting omicron in Denmark and the United Kingdom, Herlihy continued, leading to changes in case rates there. She said officials here are still tracking the new sub-strain and that it’s difficult to know what it could bring to the state going forward. But she noted that vaccines still work well against it and that omicron immunity in the broader population will help blunt its path.

Denver, Adams, Arapahoe counties to end mask orders as metro reaches ‘pivot point’ in pandemic

“We don’t necessarily expect to see the same sort of large waves with that same delta to omicron switch,” she said, referring to the surge in cases that came when omicron became the dominant strain in late December. Research has indicated immunity to delta did not translate to reliable immunity against omicron.

Immunity will be a moving target heading into the future stages of the pandemic, Herlihy said, because both natural and vaccine-acquired immunity wanes. New variants – like omicron – are still likely to emerge, and their ability to evade previous immunity won’t be the same as previous strains.  

Though omicron proved capable of evading immunity and led to a high number of infections among vaccinated Coloradans, data still indicates inoculations’ efficacy in keeping people alive and out of the hospital. Data presented to the Jefferson County Board of Health on Thursday showed that people who were fully vaccinated and boosted were 58.8 times less likely to die than the unvaccinated from omicron. They were also 17.3 times less likely to be hospitalized than those who hadn’t been vaccinated.

Broad immunity from omicron surge may bring peaceful months, Colorado modeling projects

Herlihy said the state has seen a “significant risk difference” in terms of death and hospitalization between vaccinated and unvaccinated residents.

The downturn in cases and hospitalizations have spurred every health department in the metro area who had a mask order to unwind it. Mandates in Denver and Broomfield will end Friday, those in Adams and Arapahoe counties will follow suit Saturday, and Jefferson County is planning to pull its requirement on Feb. 18. Officials in those counties said they were heartened by the improvement and in modeling, which forecasted that things would continue to improve even if changes – like required masking – were made.

Scott Bookman, Colorado’s incident commander for COVID-19, said Thursday that metro counties “are making the right decisions for their jurisdictions at the right time.” He urged Coloradans to continue wearing masks indoors, given the still-high levels of spread in the state.