Fewer than 2% of cases involved fully vaccinated

Fewer than 2% of the COVID-19 cases confirmed in Colorado since mid-January have involved people fully vaccinated against the virus, according to data released Wednesday that demonstrates just how rare it is to get the disease once protected.

Colorado is seeing a decline in new cases of COVID19, which public health officials largely have attributed to rising levels of vaccination. There are still some instances of Coloradans having what are known as “breakthrough” infections, which occur when people who have received one or both shots still become sick with the virus.

Since Jan. 15, there have been 168,944 confirmed cases of COVID-19 in Colorado, state records show. Of those, only 2,916 cases — or 1.7% of the total — occurred among fully vaccinated Coloradans, according to the state Department of Public Health and Environment.

Only 0.1% of all fully vaccinated Coloradans have developed a confirmed infection. It is expected that as more people become inoculated, the number of breakthrough cases also will increase, said Nisha Alden, respiratory disease and COVID-19 surveillance manager for the state health department, during a briefing Wednesday.

“This is not unexpected,” she said. “We have not identified more cases than we would have expected given current vaccination and transmission rates.”

Breakthrough cases are going to happen because the coronavirus is still circulating through the community

and people are starting to gather now that most public health restrictions have been lifted, said Dr. Jon Samet, dean of the Colorado School of Public Health.

“This is part of our new existence as vaccinated individuals,” he said. “The virus is still out there.”

The breakthrough cases are occurring among all age groups. The vaccines also are effective against variants of the coronavirus, as the health department has not yet found they are breaking through the protection, Alden said.

Those who get COVID-19 despite being vaccinated are more likely to have mild cases. However, 218 fully vaccinated people have been hospitalized with the coronavirus in Colorado. And 38 vaccinated people have died with the virus in Colorado, according to the Department of Public Health and Environment.

The state health department does not have data on how many of the 427 people hospitalized with the virus statewide are vaccinated, with a spokesperson saying that they cannot release the information because of patient privacy.

COVID-19 hospitalizations have decreased in counties with higher vaccination rates. For example, more than 60% of eligible residents in Summit County are inoculated and the 14-day average for hospitalizations there is zero, according to the state health department.

Hospitalization rates have been higher in Mesa County, where only 38% of residents are fully vaccinated.

In Denver, 70% of people 12 years and older have received at least one dose of COVID-19 vaccine — a threshold that means the city has reached President Joe Biden’s goal of administering at least one dose to 70% of adults by July 4, according to a news release from the city.

So far almost 2.7 million Coloradans are fully immunized and an additional 404,301 people are partially immunized.