Too early to tell if rising COVID-19 positivity start of new Colorado wave, officials say

By: - March 28, 2022 3:33 pm

Dr. Rachel Herlihy, the state epidemiologist, speaks during a news briefing on COVID-19 held Aug. 2, 2021. (Screenshot/Governor Jared Polis Facebook page)

Colorado’s COVID-19 testing percent positivity has increased slightly, but state health officials say it is too early to tell if the uptick is a true change in trajectory.

State epidemiologist Dr. Rachel Herlihy said the state’s positivity rate — the percentage of COVID-19 tests that have returned positive over the past week — sits at 3.3% on Monday, up from 2.5% earlier this month. It is a far cry from the near 30% positivity rate Colorado experienced at the height of the omicron wave in January.

“I will be closely watching that percent positivity value to see if that continues to go up,” Herlihy said. “And then if we start to see an increase in cases, that could potentially be associated with another wave of illness.”


An increase in percent positivity can sometimes be an early warning sign for an increase in cases and hospitalizations. There were 135 COVID-19 hospitalizations as of March 22, nearly the lowest of the entire pandemic.

Herlihy said that an omicron subvariant called BA.2 is present in half of the 47 wastewater utilities the state is monitoring and could account for 21% of new cases. Cases are rising along the East Coast and in Europe with the emergence of BA.2, which Herlihy said may be more contagious than the original omicron. A future rise in cases in Colorado may be associated with that variant.

Heather Roth, the immunization branch chief for the Colorado Department of Public Health and Environment, said the state is anticipating the federal approval of a second booster dose for certain demographics as early as Tuesday. She said it is likely federal regulators will approve that additional dose for people 50 years and older.

“We anticipate this being an optional recommendation, not a full official recommendation,” she said, adding that a person’s current risk factors, any comorbidities and age will likely play a role in their decision to get another shot.

As federal funding to combat the pandemic wanes, Roth said Colorado has enough vaccine stock for any more initial two-dose series and pediatric needs. The scope and demand for a second booster, however, could stretch the state’s supply.

Last month, Gov. Jared Polis rolled out the state’s transition plan as the pandemic subsides. That focuses on bolstering the health care work force and hospital capacities to best handle future surges.


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Sara Wilson
Sara Wilson

Sara Wilson covers state government, Colorado's congressional delegation, energy and other stories for Newsline. She formerly was a reporter for The Pueblo Chieftain, where she covered politics and government in southern Colorado. Wilson earned a master's degree in journalism from Northwestern University, and as a student she reported on Congress and other federal beats in Washington, D.C.