Curious about the relationship between delta COVID-19 and Idaho vaccinations? Check out these maps

People in areas with higher uptake of the vaccine may be more inclined to take precautions. But that’s not the whole story.

By: - November 4, 2021 4:47 am
Graphic showing two maps of the state of Idaho, with COVID-19 vaccination rates by ZIP code and new case rates by ZIP code from June through September 2021.

This graphic shows COVID-19 vaccination rates by ZIP code, among eligible age groups; and new COVID-19 case rates per capita by ZIP code, from June through September 2021. (Audrey Dutton, Idaho Capital Sun)

The coronavirus thrives in communities with low immunity. During summer and fall, the fast-spreading delta variant invaded Idaho and tore through pockets of the state that have low vaccination rates.

The Idaho Capital Sun mapped and analyzed COVID-19 data at the county and ZIP code levels, using data from the Idaho Division of Public Health and U.S. Centers for Disease Control and Prevention. The data include COVID-19 cases reported each week from late June through late September, and vaccination rates as of late September. The records contain no information that could be used to identify anyone.

Idaho’s deputy state epidemiologist and COVID-19 data expert, Dr. Kathryn Turner, explained why a relationship appears to exist between vaccination rates and outbreaks in each community.

“There’s a reason why I use the term ‘community immunity’ instead of ‘herd immunity’ is because it’s really about that level of protection that exists in the community in which you operate,” Turner said in an interview in September. Maps based on the data “are actually telling the story about (how) vaccination is an individual choice, and it is about protecting yourself, but in the larger context, it’s really about protecting each other.”

The Sun asked Turner if it’s possible that highly vaccinated communities also take other precautions, like universal masking?

“There’s some truth in that a person who proactively went and got vaccinated is more likely to follow public health recommendations, for sure,” she said. “But I do think there’s going to be vaccinated people who did it because of x reason (such as an employer requirement), and they are not going to mask up and are not going to social distance.”

What about “natural” immunity among people who recovered from COVID-19? Why did communities like the Magic Valley that already suffered a huge surge in the fall, once again have such large numbers of new infections?

“Natural” immunity wanes, Turner said, “so it’s not a guarantee that you’re not going to get reinfected.”

Public health experts and vaccine research back up that statement. The COVID-19 vaccines available to Idahoans have shown a higher level of resistance to infection, and especially to severe disease.

South Central Idaho “acts a little bit different, because you’ve got Hailey and Ketchum (in Blaine County), and then everything around it, and they’re not the same,” Turner said.

Blaine County has one of the highest vaccinations rates in the U.S. and, by far, the highest rate in Idaho.

The Treasure Valley is a case study of different responses to the same threat. Boise schools and Boise city government reopened but required masks regardless of vaccination status. Meanwhile, the West Ada School District that includes Meridian and Eagle began the school year with a rule that parents could opt their children out of wearing masks.


The Idaho Panhandle has suffered the longest surge of COVID-19 in the state. It moved into crisis standards of care in early September and remains overburdened by coronavirus patients, two months later.

Kootenai Health in Coeur d’Alene in normal times has 26 critical care beds, said Dr. Karen Cabell, chief physician executive. On Wednesday, it had 27 critical care patients with COVID-19, and about 20 patients who needed ICU care for other reasons.

Kootenai Health is licensed for about 330 total inpatient beds. On Wednesday, 95 of them were taken up by COVID-19 patients, Cabell said. She compared that with Spokane, where four major hospitals with a total of about 1,200 beds had only 114 patients with COVID-19.

“You have the data that show that we have low vaccination rates in this area,” Cabell said. “And we continued, throughout the late summer and early fall, to not have social measures in place. … All but one small school system had no mask mandates, no social distancing guidelines in place.”

Health officials on Tuesday said that COVID-19 numbers are starting to slow their pace in North Idaho.

But, said Public Health Administrator Elke Shaw-Tulloch, “unfortunately, six of the seven counties with the highest weekly incidence rate are located in eastern Idaho, so we’re keeping a watchful eye.”

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Audrey Dutton
Audrey Dutton

Audrey Dutton, senior investigative reporter, joined the Idaho Capital Sun after 10 years at the Idaho Statesman. Her favorite topics to cover include health care, business, consumer protection issues and white collar crime. Dutton hails from Twin Falls. She attended college at Hamline University in St. Paul, Minnesota, and received a master's degree in journalism from Columbia University in New York City. Before coming home to Idaho, Dutton worked as a journalist in Minnesota, New York, Maryland and Washington, D.C. Dutton's work has earned dozens of state, regional and national awards for investigative reporting, health care and business reporting, radio journalism, data visualization and much more.