Local public health officials and analysts implored the public not to let its guard down as the omicron variant drives a dramatic COVID surge in Colorado.

“We believe it is important for Coloradans to know that there is a high probability of coming into contact with someone with (coronavirus) in the days ahead,” a statement from the COVID-19 tracking team led by the Colorado School of Public Health said.

The new virus variant is driving record-shattering numbers of recorded new daily cases, and the number of patients currently hospitalized with COVID-19 in Colorado has spiked back up since late December. That number was 1,374 confirmed COVID-19 patients as of Jan. 7, according to state data.

“Even though infection from the Omicron variant appears to result in lower risk of hospitalization than the Delta variant, hospital demand could exceed prior peaks based on high number of cases caused by Omicron and its ability to cause infection among previously vaccinated or infected individuals,” said the Jan. 3 statement from the Colorado COVID-19 Modeling Group, a team that analyzes data to provide projections on how the pandemic will continue to unfold.

The virus is spreading at record rates in Adams, Arapahoe and Douglas counties, for example, according to Tri-County Health Department.

“These next few weeks are likely to be among the most challenging we have faced over the past year,” Dr. John Douglas, executive director of Tri-County Health, said in a news release.

According to Tri-County Health data, 3,193 new cases were reported on Dec. 31 across the three counties, the most on any single day since the start of the pandemic up to that point, the agency said in the release.

All three counties have exceeded their all-time high seven-day incidence rates — which were previously set in November 2020 — with rates exceeding 1,000 cases per 100,000 people in each, according to the release. (“Incidence rate” means the rate of new cases.)

“Over the past two weeks, Adams County rates increased by 403%, Arapahoe County by 437%, and Douglas County by 480%,” Tri-County said in the Jan. 5 release.

In addition, COVID test-positivity rates are also at record levels, greater than 25% in each county, according to the release, referring to the percentage of tests that come back positive.

“Although hospitalization rates have not risen as much thus far, hospital capacity in our counties and region remains critically tight,” the release added.

Omicron has rapidly become the dominant variant, now making up virtually 100% of Colorado COVID-19 cases, the release said, citing state data.

“The highly infectious nature of this variant means that this wave could be shorter but also more severe than prior waves,” the school of public health’s statement said. “We are most concerned about unvaccinated and immunocompromised individuals, who face the greatest risk of severe COVID-19 due to Omicron infection.”

Tri-County Health urged getting a COVID-19 vaccine, or a booster for those who have had the initial shots, as soon as possible.

“It is increasingly clear that boosters are critical to optimize protection against the Omicron variant, with estimates by the Centers for Disease Control and Prevention (CDC) that protection may (now) be no better than 35% after two doses in contrast to 75% after a booster,” Tri-County said in the release. New variants have affected the effectiveness of the initial vaccine shots.

The longer the COVID-19 pandemic continues, the higher the likelihood of new variants emerging becomes.

“Most importantly, fully up-to-date vaccines remain the most critical public health measure to protect people from COVID-19, (to) slow transmission, reduce the likelihood of new variants emerging and prevent serious illness, hospitalizations and death,” the agency continued.

As of Jan. 1, over 75% of individuals 12 and older have received initial doses of vaccines in Adams, Arapahoe and Douglas counties, although only 40% to 50% of those who are currently eligible for boosters have received them, according to Tri-County.