The U.S. Centers for Disease Control and Prevention (CDC) on Friday, August 6, updated a Colorado county where vaccines were not so effective against the Delta variant.

Mesa County of Colorado was one of the early places hit by the Delta variant in the U.S., now the new release by the CDC says it has more breakthrough cases than the other places in the state.

According to the report, vaccine effectiveness measured in Mesa county was only 78%, 11% lower than the statistics found in other Colorado counties. The study also noted the breakthrough cases in the over 65s in Mesa were 10.1% higher than the rest of the state.

From that figure, the agency said the vaccines may not be too protective against symptomatic infection with the Delta variant and continued to advise “enhanced mitigation strategies, including masking in indoor settings.”

However, the report did not include the proportions of infections between the county’s unvaccinated and vaccinated COVID-19 patients. 

The CDC reported that between April 27 and June 6, 2021, the county reported more severe illnesses and ICU admissions than in other counties of the state. But it had not been clear the ratio of such between the breakthrough cases and the unvaccinated patients.

The report said it took just five weeks for the Delta variant to spread from just taking over 43% of the overall infections in Mesa to rocketed by 88% between May 5 and early June. During that period, vaccination rates in the county were somewhat modest, with only 36% of the eligible population fully vaccinated. 

At least, according to data by the New York Times, the county was seeing the less dramatic manifestation of COVID-19 during the past two weeks. 

Hospitalizations had decreased by 33% in a 14 days period, with 6 cases of fatalities. As of August 6, the 7-day average of new infections reduced to 25 cases, a reduction by nearly half of the proportion compared to June 1, which was 51 cases. 

After the CDC updated its new mask guideline during the end of July, the Mesa county health department said it would not plan to impose a mask mandate.

While still suggesting citizens be watchful of infections, the department said the recommendations work best “when used appropriately and in accordance with individual needs,” according to NBC11 News.

The Aspen Times revealed that Mesa had tried to encourage more citizens to get vaccinated with incentives. Vaccinated people can get a chance of winning up to $90,000. 

But the outlet noted that such an amount of money had not been influential since people seeking the jabs in the county remained minimum. 

Many residents had expressed they could not trust the doses and were determined to stick with their own choice.

“I don’t think enough was done,” a resident spoke of the process of developing the vaccines. “I think we’re rushing a lot of things. We don’t know the effects down the road.”

In its August 6 report about the breakthrough cases in Mesa, the CDC noted the variant was capable of causing more acute illnesses in patients and reminded that the vaccine was “a critical strategy for preventing infection, serious illness, and death from COVID-19.”