Editor's note: This page will be updated frequently but may not contain the latest information. Please refer to the sources listed throughout and at the end of the article for the latest updates on the pandemic.

As of September 3, 2022, Colorado has had more than 1.6 million confirmed cases of COVID-19, with more than 13,901 deaths due to the disease. More than two years after the pandemic began, the state is now seeing much lower case numbers and transmissions rates, although the virus remains in circulation. All Coloradans ages five and older are now eligible for the COVID vaccines. Thanks to these vaccines, restrictions such as mask mandates and business closures, which were put in place at the beginning of the pandemic and used at various times to temper spikes in cases, have been lifted, and much of the state operates as normal.

Some 71 percent of the state's population (about 4.1 million people) has been fully vaccinated against the virus, even as the rise of new variants continues to be of concern. Public health officials continue to encourage vaccination and hand-washing to keep COVID-19 case numbers down. 

Origins

COVID-19 is caused by a novel coronavirus. Discovered in the 1960s, coronaviruses are a large family of viruses that include the common cold as well as Severe Acute Respiratory Syndrome (SARS), a coronavirus that killed 770 people worldwide in 2002–03. Coronaviruses infect humans as well as animals, such as bats and cattle. On January 7, 2020, Chinese officials first detected COVID-19 while investigating a cluster of pneumonia cases in China’s Wuhan province. The coronavirus responsible for the current outbreak was previously known to infect only bats. It was initially believed to have been transmitted to humans from a wet market in Wuhan province, a theory that has since been confirmed. The virus quickly raced through Chinese populations, infecting some 550 people and killing 17 by January 22.

On January 19, 2020, providers at a clinic in Snohomish County, Washington, identified the first COVID-19 case in the United States. The thirty-five-year-old man said he had recently returned from visiting family in Wuhan, China. The man was hospitalized with symptoms including cough, fever, nausea, and vomiting, but made a full recovery after twelve days. Although his was the first documented case, researchers now suspect that the virus was circulating in the United States as early as mid-December 2019.

Colorado Outbreak

The new coronavirus apparently came to Colorado via a traveler who visited Italy, one of the hardest-hit nations during the first wave of the pandemic. A man in his thirties arrived at Denver International Airport on February 29, then rented a car and drove to a condo at Keystone Resort in Summit County. The man, who is not a resident of the state, developed a respiratory illness and went to St. Anthony Summit Medical Center in Frisco, where on March 5 he became the first person in Colorado to be diagnosed with COVID-19.

Six days later, as the virus continued to spread worldwide, the WHO declared the outbreak a pandemic, a designation reserved for global outbreaks of new diseases. The virus has a two- to fourteen-day incubation period, meaning infected persons will not show symptoms until between two days and two weeks after exposure. In Colorado, cases were heavily concentrated in urban counties, especially Denver and its suburbs. As cases continued to spread throughout Colorado’s heavily trafficked ski areas, many of the resorts decided to close their doors, sending economic shockwaves through ski resort communities. Weld and other agricultural counties also saw outbreaks. The first wave of the pandemic deeply affected the state’s economy, with hundreds of thousands of unemployment claims submitted to the Colorado Department of Labor and Environment.

Initial Response

Coloradans spent nearly four weeks under a statewide stay-at-home order until a flattening curve in the rate of infection allowed Governor Jared Polis to announce a gradual reopening of the state on April 21, 2020. The state managed to avoid additional lockdowns throughout the next two years, even as cases spiked in fall 2020. As face masks were shown to drastically reduce viral spread, the state and counties enacted mask mandates throughout the initial wave. Although they proved controversial in many places, the mask mandates were relied upon to keep case numbers down during intense surges of variants over the next two years.

Testing for the new virus was important to track and control infections, but it proved a challenging bottleneck early on, in part to a lackluster federal response. In the first few weeks of the outbreak, Colorado was only able to test 250 people per day, but testing was subsequently expanded. On March 19, 2020, San Miguel County became the first county in the United States to announce test availability for all of its residents, thanks to funding from United Biomedical, whose owners had a house in Telluride. 

On June 2, 2020, officials announced that anyone with symptoms could get tested at Ball Arena (formerly the Pepsi Center) in downtown Denver. In mid-July officials had to close the facility early due to overwhelming demand on labs, which they feared would cause a delay in getting results out to those tested. By late July, those who got tested still had to wait several days - in many cases, up to eight or more - to get results. Meanwhile, scientists at the University of Colorado began testing a faster, saliva-based test for broader community application. Eventually, testing availability expanded throughout the state, and home-test kits were also developed.

Vaccine

On December 14, 2020, the first shipment of Pfizer Corporation's COVID-19 vaccine arrived in Colorado. The vaccines were developed using technology that had been evolving for decades, and they went through several clinical trials before they were approved for public use.

The first person to be vaccinated in the state was respiratory therapist Kevin Londrigan at Fort Collins Hospital; he was surrounded by media and Governor Jared Polis as he received the first of two injections. The state released the vaccine in phases, beginning with front-line healthcare workers and high-risk individuals (Phase 1A), then moving on to healthcare workers with less direct exposure, home health and hospice workers, as well as correctional, police, and other emergency staff (1B). Next, in the spring, those over the age of sixty-five and with existing health complications, as well as teachers, grocery store workers, and those who work in food processing became eligible for the vaccines (Phase 2).

By April 2, 2021, all Coloradans age sixteen and older were eligible for the vaccine, and that spring an unprecedented clinical trial of the vaccine for younger children was underway at Children's Hospital in Aurora. The results of the trial were submitted to the Food and Drug Administration (FDA) in October 2021, and the FDA approved vaccines for children 5 and up in early November.

Despite the state's relatively strong rollout of the vaccine, many Coloradans refused the shot, and disparities were found along racial lines. Although 22 percent of the state population is Latino, by April that population had received only 8 percent of vaccine doses, while white Coloradans had received 72 percent of all vaccinations (whites make up 67 percent of the population). Black Coloradans, who represent 4 percent of the state population, had only received 2 percent of all vaccinations. These trends mirrored similar disparities in nearly every other US state, and were due to a combination of voluntary hesitancy and lack of access or availability.

Variants

The Delta variant of COVID-19, originally identified in India, swept through the state in the summer and fall of 2021, causing a spike in cases, hospitalizations, and deaths, especially among unvaccinated residents. The surge continued to overwhelm hospitals statewide through late fall, but due to relatively high vaccination rates, Polis and state health officials resisted imposing a statewide mask mandate or lockdown. On November 28, 2021, after a request from Polis, healthcare servicemen and women from the Department of Defense arrived in some Colorado hospitals to assist overburdened staff.

In early December, at the tail end of the Delta surge, a new variant, Omicron, made its way to the state. The variant is more transmissible than Delta, although it typically presents far milder symptoms. 

Resources

The most reliable information on the coronavirus pandemic comes from the CDC as well as the Colorado Department of Health & Environment. Reliable media sources include Colorado Public Radio (CPR) and the Colorado Sun, which features a live-updated map of documented cases.