More vaccinations means fewer COVID cases in Colorado – typically

The parts of Colorado where more people are vaccinated have fewer cases of COVID-19 overall, but some counties where few people are vaccinated appear to be lucky to avoid a peak this spring.

The question is whether that chance will hold up if their residents continue to go unvaccinated – especially with more contagious variants lurking in the state. Mesa County approached running out of hospital beds earlier this month as the delta variant, which spreads more easily and can be deadlier, moved through a population where two-thirds of people remained unprotected.

These counties shouldn’t count on it, according to Beth Carlton, associate professor of environmental and occupational health at the Colorado School of Public Health.

“If counties have low vaccination rates, now is the time to tackle that, especially with the delta variant,” she said.

Getting the vaccine now is especially important, she said, because one dose of the vaccine offers significantly less protection against delta than against other forms of the virus, and it takes five to six weeks to reach the level. highest immunity.

In Colorado counties of more than 100,000 people, the link between more vaccinations and fewer cases is easy to see, with exceptions in a dozen small counties. Large counties where more than half the population is fully vaccinated, such as Jefferson County, had about half as many cases, relative to the population, as the general condition during the first two weeks of June.

At the other end of the spectrum, El Paso County, where just over a third of residents are vaccinated, has seen nearly double the rate of cases statewide.

The disparity is even more pronounced in Mesa County, where the rate of new cases was four times that of the state. This may be at least partially due to the spread of the delta variant among unvaccinated people, Mesa County public health spokeswoman Amanda Mayle said.

Most cases of the delta variant are found in Mesa and El Paso counties, although they represent about 40% of the variant cases found statewide in the last week – suggesting that it is starting to oust previous versions of the virus. This matches the global evidence, where the delta variant caused a spike in highly vaccinated countries, like the UK.

So far, the delta variant has not been found in the eastern plains, which are among the least vaccinated areas of Colorado. They will always have to be vigilant, said Trish McClain, director of public health at the Northeast Colorado Department of Health.

Colorado’s first cases of the alpha variant, previously known as B.1.1.7, were found at a nursing home in Simla. Alpha was more contagious than the original version of the virus, but was eclipsed by Delta.

“I haven’t been able to figure out a rhyme or a reason why the variants appear,” she said. “It’s a guessing game.”

It’s also not clear whether the variants have anything to do with two exceptions to the correlation between vaccination and lower cases – San Miguel and Gunnison counties in western Colorado.

San Miguel County experiences higher levels of transmission despite 64% of its population being fully vaccinated. That’s because her vaccination rates vary in different parts of the county, said Lindsey Mills, public information consultant for San Miguel County public health. The county case rate was about three times the state average during the first half of June.

More than two-thirds of cases come from the less populated western part of the county where fewer people are vaccinated, Mills said. The remaining cases are mostly mild and breakthrough infections in the eastern part of the county, which is more populated and attracts tourists.

“We have a very diverse community with different views on vaccines and use in general,” she said, adding, “For the smaller population to have these outbreaks, a lot of this is due to to social gatherings and home transmission. “

Gunnison County has also had slightly more cases of COVID-19 than the state as a whole, despite an above-average vaccination rate – 59% fully protected.

Joni Reynolds, program director for Gunnison County public health, said she was not sure the rate reflected the real situation, however. In smaller counties, the spread of the virus within a single family can skew the numbers, she said. Gunnison County has a population of approximately 17,000.

“In a bigger county or a bigger population it gets diluted,” she said.

Six of the 10 counties with the lowest case rates also had below-average vaccination rates, and all but one, Morgan County, have fewer than 5,000 residents.

Statistics fluctuate more in small populations, and the number of cases may be less reliable in rural areas with younger populations, who are less likely to develop symptoms or know they should get tested, Carlton said. .

And it is possible that the number of cases is underestimated in some counties of the Eastern Plains because it is not easy to get tested, said Trish McClain, director of public health at the Northeast Department of Health. eastern Colorado. For example, in Washington County, the state sends out a mobile test unit once a week, she said.

The region’s agriculture-centric economy could also help, as the virus is less likely to spread in outdoor workplaces, McClain said.