Hundreds of COVID-19 deaths and thousands of hospitalizations in Colorado can be prevented in the coming weeks if the state successfully pushes out booster and pediatric vaccine doses, a team of researchers said Friday.

The peak of the fifth pandemic wave currently washing over the state is still likely a month away, the team, which regularly models how the pandemic will look in the near term, wrote in their latest report. But extent and size of that apex can be blunted by stepping up immunization drives, increasing social distancing and masking, and the use of monoclonal antibody treatments, the experts wrote.

The experts also discussed several potential explanations for why COVID-19 is currently surging here, a question state leaders have been asked repeatedly for weeks. The explanation is likely multifactorial, the team said, with pockets of unvaccinated residents, waning immunity and increased mingling by Coloradans all playing parts. But the team found no “evidence that a decrease in mask wearing is driving the current surge,” addressing another criticism Gov. Jared Polis – who has resisted instituting another mask order – has faced of late.

Though explanations vary, there is no question that relief for Colorado’s hospitals is needed. On Friday, there were fewer than 100 intensive care beds left in the entire state of Colorado. Though that number can fluctuate even within a single 24-hour period, it’s an unprecedented press on high-level care capacity, hospital and state officials said this week, and it prompted hospitals to meet daily to facilitate statewide transfers of patients between facilities. Overall bed availability is also at its lowest point of the pandemic. 

COVID-19 is playing an exacerbating role in limiting capacity, but officials say a combination of factors – the pandemic, increased trauma cases, increased and more severe “typical” medical emergencies, staffing shortages – are pressing upon them at once. 

Of those issues, though, officials have said COVID-19 is the easiest to blunt because of the availability of vaccines, booster doses and critical behavioral changes like masking and staying home. The modelers write that one in 48 Coloradans are currently infectious with COVID-19, one of the highest levels of the pandemic. On the current trajectory, hospitalizations from COVID-19 will continue to increase for the next month, the team wrote, though the surge is unlikely to hit December 2020 levels.

“Colorado now has the 10th highest COVID-19 hospital demand in the United States,” the team wrote. “It is one of 11 states where COVID-19 hospital demand is rising and has the second-highest rate of increase among the 11.”

The solutions to the crisis offered in the report are already readily available here. Gov. Jared Polis and other state leaders have pushed for more widespread use of monoclonal antibody treatments, which, when given shortly after high-risk patients become ill, can significantly reduce the risk of hospitalization. The state is set to deploy five mobile clinics to distribute the treatment. The modelers estimate that increasing availability and use of the antibodies “can reduce COVID-19 hospital demand by 12-23%.”

More critically, booster shots are broadly available statewide and have already been pushed into long-term care facilities, where residents remain most vulnerable to hospitalization and death. Federal regulators have cleared pediatric vaccines for children between the ages of 5 and 11, and clinics for those kids have already started in Colorado. The state’s goal, officials have said, is to at least partially vaccine 50% of the 480,000 Colorado children in that age group by Jan. 31.

On the current trajectory, the modeling team projects roughly 15,000 COVID-19 hospitalizations in Colorado between now and the end of February, plus more than 2,000 additional deaths from the disease. That scenario also assumes transmission control – meaning the use of masks, social distancing and other methods to blunt spread – don’t worsen. If they do, thousands more hospitalizations and hundreds more deaths will occur; that scenario would be even worse without pediatric vaccines.

But, if 75% of the eligible population statewide gets a booster by the end of the year, the state may avoid hundreds of deaths and thousands of hospitalizations, even if people don’t change their behavior to slow spread. 

“In terms of measures to take to end the surge, this explanation points to the need for a two-pronged strategy of strengthening the application of non-pharmaceutical interventions (like masking and social distancing) while pushing to vaccinate the unvaccinated, provide booster shots, and vigorously implement vaccination programs for those 5-11 years old,” the team concluded.

Why Colorado?

As the surge has continued in recent weeks, Polis and state health officials have been repeatedly asked why Colorado is facing a significant surge, despite a relatively high vaccination rate and as the pandemic’s burden in much of the rest of the country lessens.

The governor and others have said answers remain allusive. But the modeling team considered several explanations. An unsurprising but significant contributor are the “pockets of unvaccinated populations” statewide, the researchers wrote.

“Vaccinated individuals in high-vaccination regions have the lowest hospital and mortality rates in the state,” they said. “Conversely, unvaccinated individuals in low-vaccination regions have the highest hospital and mortality rates in the state.”  

Waning vaccine immunity is also likely playing a role, though roughly 80% of hospitalizations are among the unvaccinated, as are the bulk of recents deaths. So, too, is increased mobility of Coloradans: “Population movement is at or beyond pre-pandemic levels,” the team said. 

Schools, which reopened right as this surge in cases and hospitalizations began to pick up pace, do not explain the rise in patients admitted to facilities here, the researchers wrote. The increasingly cold weather, which traditionally heralds the beginning of respiratory season each fall, likely plays a “modest role.”

Though the use of non-pharmaceutical interventions – things like social distancing, masking, washing hands and staying home – is more limited now, the team said it couldn’t attribute the latest surge to a lack of masking.

“Facebook survey data do not show a sharp downtown in reported use of masks coincident with the timing of the surge,” they said. “In fact, there is a gradual increase in mask wearing, particularly in Boulder and Larimer counties, which recently implemented mask mandates, which may explain why Colorado’s increase in SARS-CoV-2 spread has been more gradual than other states. We do not see evidence that a decrease in mask wearing is driving the current surge.”