The state is still in the midst of its second-largest surge of COVID-19, and the variants of the virus that are circulating are harder to control.
This story was originally published in the Colorado Sun
When Gov. Jared Polis walked to the lectern Friday to announce the effective end of Colorado's statewide mask mandate, he did so with a smile uncovered for all to see.
"This is a big step," Polis said. "We've really reached a level of immunity where the pandemic isn't over, but where we are safer."
But, as he spoke, the coronavirus continued to tear through Colorado at levels rarely seen before in the pandemic. Colorado on Sunday sat atop a New York Times tracker for national hotspots, recording the worst 7-day average rate for new coronavirus cases in the nation. (It first rose to the top spot on Friday.)
Measurements of how well the virus is under control are near the lowest they've been since the start of the pandemic. An estimated one out of every 81 people in the state is currently contagious with the virus. In March, that number was one out of every 350 people.
The most recent modeling projections produced by health experts at several Colorado universities estimate more virus will be in circulation this coming summer than last summer. And the virus that is circulating will be predominantly from more infectious variants - most of the cases in the state now come from the B.1.1.7 variant, which is believed to be 50% more transmissible than older strains.
For weeks, the modeling projections have issued a dire warning: If the state relaxes restrictions now, more people will die from the virus by the end of July than if restrictions remain in place for a little while longer.
The high rate of spread poses a problem even for people who have been vaccinated.
"The more infections we have circulating, the more vaccine breakthrough that we'll see, the harder everyone's life is," said Elizabeth Carlton, an epidemiologist at the Colorado School of Public Health.
The risk is greatest, though, for those who are unvaccinated or who are still in the process of reaching full immunization.
"It is possible to see some increase in severe disease if those who are not fully vaccinated decide the pandemic is over," Carlton said.
But despite these concerns, Colorado is largely dropping coronavirus restrictions. In addition to the end of much of the statewide mask order, Colorado will no longer require state approval for large events as of June 1.
Counties in metro Denver moved over the weekend to "level clear," which ends most capacity restrictions at bars or restaurants. The counties also aligned their local mask orders with the states, requiring face coverings in only a small number of settings, such as nursing homes and child care facilities. Many other counties around the state had already ended their local restrictions.
Here's what you need to know about current coronavirus trends in Colorado as the state returns to normal-ish:
Lots of counties are seeing high levels of transmission
As of Sunday, 28 counties in Colorado had one-week incidence rates for COVID-19 that the Centers for Disease Control and Prevention would categorize as "very high" - the highest level.
That includes most counties on the Interstate 25 urban corridor from Larimer to Pueblo, except for Boulder, Broomfield, Douglas and Denver counties.
Looking at it another way, if the state were still operating under its original dial framework, 11 Colorado counties would currently have red-level incidence rates. If the state still had its most recent version of the dial, which had more relaxed standards, two counties would be in level red, three more would be in level orange and 23 would be in level yellow.
"We think there are a lot of infected people in Colorado right now," Carlton said.
The fourth wave is Colorado's second-largest
Colorado is still in the midst of its fourth wave of the virus - the first three occurred in the spring of 2020, following the Fourth of July last year, and this past winter. The third wave was, by far, the biggest. But the fourth wave is estimated to be the state's second-largest.
With much of the state's older population now vaccinated, the fourth wave has been defined by high infection rates among younger Coloradans, especially kids who are middle- or high-school-aged. That has meant a smaller rise in hospitalizations and deaths than during previous waves. But there's still been an uptick in both.
As of Sunday, there were 563 people with coronavirus in Colorado hospitals, a drop from the state's peak of more than 1,800 in December, but up more than 50% since March. Around eight people with COVID-19 are dying per day in Colorado currently, compared to around four to five people per day in March.
The fourth wave appears to have crested
After more than a month of steadily climbing, rates of new coronavirus cases in Colorado are on the decline. Hospitalizations appear to be, as well.
"This is certainly a great sign, and this decline appears to be occurring in all age groups, as well," Dr. Rachel Herlihy, the state epidemiologist, told reporters on Thursday.
Infection rates are still quite high, though. The state has been seeing more than 1,000 new cases per day. At the lowest point of the pandemic last summer, Colorado identified about 165 new cases per day.
Control of the virus is near a pandemic low
When making projections about the course of the pandemic in the state, the Colorado COVID-19 Modeling Group, the team of university researchers that includes Carlton, estimates a figure called "transmission control." It's a number that captures the cumulative impact of everything we're doing in the state to control the virus: social distancing, staying at home, mask-wearing, etc.
In its latest report, the team estimates transmission control at 59%, a slight improvement over the previous week but otherwise one of the lowest percentages estimated during the pandemic.
Not all of this is down to Coloradans partying like it's 2019. Based on individual behavior, alone, transmission control is around average. The variants currently circulating simply demand a higher level of precautions to be kept in check.
But Carlton said it's also important to take vaccinations into account when thinking about transmission control.
"The good news is we can tolerate lower levels of transmission control now because more people are vaccinated," she said. "Provided we continue to roll out vaccines and continue to hit targets on vaccination, there is room for transmission control levels in the 50s. That's the power of the vaccines."
The New York Times' tracker hints at this. While Colorado on Sunday had the worst rate of new coronavirus cases in the nation, it ranked 13th for current hospitalization rate and eighth for the current rate of COVID-19 deaths.
Less than half the state is immune
The end to most statewide coronavirus restrictions comes at a time when the majority of people in Colorado are probably still susceptible to infection.
As of Friday, about 2.3 million people in Colorado were fully immunized - roughly 40% of the state. Immunity acquired through having been infected by the virus adds to that percentage, but likely not a whole lot.
The modeling team estimated in its latest report that, as of May 10, about 48% of the state is immune to the virus either because of vaccination or infection.
But that number isn't durable. It will decline over time as people's immunity fades. Currently, Carlton said researchers estimate that people who were infected but didn't have symptoms lose their immunity after 6 months. People who were infected and did have symptoms lose it after a year. And immunity from the vaccines may also decline over time.
That means people may cycle back into being susceptible, becoming fodder for new infections.
Dropping restrictions now will likely mean more deaths
For weeks, the modeling team has forecast what would happen if Colorado drops restrictions now as opposed to waiting. The results have been consistent: more deaths.
In the latest report, the team estimates that a 7% reduction in transmission control as a result of easing restrictions now will result in about 300 extra deaths by the end of July than the state would have otherwise seen. The number is slightly more if the state's vaccination campaign stalls out and slightly less if it picks up.
Carlton cautioned that this is an estimate that researchers are still refining. It's possible the team is overestimating the total number of deaths that will occur between now and the end of July, and it is working to better understand the lethality of the virus variants and the efficacy of the vaccines against them.
But the overall trend holds.
"Generally, there will be more deaths if fewer people get vaccinated and there will be more deaths if there are lapses in transmission control," Carlton said.
Best-case scenario: statewide herd immunity be the end of the summer
While Colorado just opened up vaccination to kids ages 12 through 15, immunizations for adults have been slowing. The latest modeling estimates are somewhat pessimistic about how fast Colorado might reach high statewide levels of immunity - either through vaccination or infection. Experts predict that herd immunity against coronavirus requires at least 70% of the population to be immune.
(Herd immunity is the level at which enough people are immune to a virus that the virus can't find enough susceptible people to infect. At that point, the level of virus in circulation begins to decline.)
Under a scenario where vaccations speed up again, the state could reach 70% immunity by August. If vaccinations stagnate, though, Colorado won't reach that threshold before the end of summer - if ever.
The high-vaccination scenario requires at least 80% of Coloradans ages 12 to 64 to get immunized. For reference, people ages 40 to 64 currently have the highest vaccination rates among the under-65 age groups in Colorado, but it is only about 50%, according to the modeling team.
The low-vaccination scenario assumes that 62% of people 40 to 64 and 50% of people 12 to 39 will get vaccinated.
State health officials remain optimistic about the chances for reaching herd immunity. Herlihy, the state epidemiologist, said Colorado "has a decent shot."
"There is the potential to reach that threshold, but it is challenging," she said.
While adults gain protection, young kids remain vulnerable
One group who can't get vaccinated, at least not yet: Kids ages 11 and under. And they remain vulnerable to infection.
"The demographics of this pandemic have been shifting," said Dr. Dawn Comstock, the executive director of Jefferson County Public Health.
But Comstock and other health leaders say they are comfortable with ending many restrictions because, even though they don't want to see kids get sick, infections are usually less severe in children. Many kids are also already going to school in-person.
"It's difficult to continue to impose restrictions on businesses when so many adults in Jefferson County have been vaccinated while we allow children to go to school full time when they have not been vaccinated," Comstock said.
Very rarely, though, coronavirus infections can cause kids to be hospitalized or die. And some children also suffer long-term symptoms from COVID-19, similar to adult "long-haulers."
We've switched from government responsibility to personal responsibility
Even while dropping most coronavirus restrictions, Polis and other leaders have urged people to remain careful, especially if unvaccinated. But it's clear they also think they've done about as much as they can do through government regulation.
"At this point, it's largely become a matter of personal responsibility," Polis said Friday. "If you want the vaccine, you've had it."
As Jefferson County and other metro-area counties move to "level clear," Comstock said health officials will be watching closely. If hospitalizations turn worryingly upward, they could reimpose restrictions.
But she also echoed Polis, that pandemic precautions are now up to the people.
"As we move out of the phase of the pandemic where we need to have large countywide restrictions, we then move into the phase of the pandemic where each individual needs to recognize their risk," she said. "If they are at higher risk, they need to take individual precautions to protect themselves."
In this new normal, Colorado health officials are already planning for possible surges of a virus that likely won't be completely leaving our state anytime soon, if ever.
Herlihy and Dr. Eric France, the chief medical officer for the Colorado Department of Public Health and Environment, said they are hopeful the virus will die down during the warm summer months. But they are looking toward fall, when respiratory viruses like the coronavirus typically make a resurgence.
France said CDPHE is currently planning for how to handle an expected fall surge. And Herlihy said that possibility is all the more reason for the state to push hard on vaccinations throughout the summer.
"The key message here," Herlihy said, "is that the more individuals that are vaccinated now, the better position that we are going to be in going into the fall and that typical respiratory illness season, when we could see the COVID-19 virus transmitted alongside flu and other respiratory viruses."
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Mark Duggan provided online production of this story for KSUT.
