DENVER (KDVR) — Health experts fear Colorado’s recent drop in COVID-19 cases could be short-lived as the omicron variant takes off in the United States.

According to state data, Colorado’s most recent wave peaked in November. Hospitalizations and case numbers have been on a steady decline for several weeks.

“We’re sort of on a downtrend from delta, but I think with omicron in play, unless something suddenly changes, we’re going to quickly uptrend again,” said Dr. Michelle Barron, senior medical director of infection prevention at UCHealth.

COVID-19 cases are currently surging in parts of the northeast and midwest. According to the Centers for Disease Control and Prevention, omicron makes up about 73% of cases nationwide. Barron said omicron data is lagging and we likely don’t know how many cases are currently present in the state.

“First you’re positive, then it gets sent to the lab, then it gets sequenced. We could be probably 10 days or maybe almost two weeks behind,” Barron said.

Early information suggests omicron is more transmissible than previous strains of the virus, but it’s unclear how the variant will impact hospitalizations. Health experts are also unsure why Colorado’s trends do not line up with the country as a whole.

“The pandemic has been really humbling to all of us, not just the health care community but the entire nation. Every time we think we have it down, we don’t know. The answer is not simple,” said Dr. Jaya Kumar, chief medical officer at Swedish Medical Center.

Colorado’s latest peak for cases and hospitalizations came at a time when the rest of the country was trending down. Kumar said there are a multitude of factors in different waves across the country, including human behavior, public health orders, the transmissibility of the virus and immunity among a population.

“We also know that immunity fades over time, including from the vaccine. The importance of boosters really comes into play,” Kumar said.