More vaccinated Idahoans got COVID-19 in July as delta variant spread. Here’s what to know.

More than 750 of the breakthrough cases occurred last month. August may be similar, health officials say.

By: - August 12, 2021 1:09 pm
Signs lead people to a COVID-19 vaccination clinic set up at a park in Caldwell.

In this file photo, signs lead people to a COVID-19 vaccination clinic set up at a park in Caldwell. Saint Al’s provides interpreter services for non-English speakers and has focused on helping Latinos get vaccinated against COVID-19.

The delta variant is burning through Idaho, spiking the state’s COVID-19 infection rates and sending more people to the hospital.

Some of those cases are among people who were fully vaccinated from the coronavirus.

Idaho has reported 1,455 such “breakthrough cases” this year. More than half of them — 757 — were people who tested positive in July, according to the Idaho Department of Health and Welfare.

The department anticipates August will hold similar numbers, according to spokesperson Niki Forbing-Orr.

The numbers may be surprising. But after a lull in outbreaks in late spring and early summer, the total number of cases among all Idahoans — vaccinated or not — surged in July.

The highly infectious delta variant is likely responsible for that, based on the state’s laboratory sequencing of virus samples in the past month.

Idahoans who don’t have vaccine protection are getting sicker and dying more often. Their infection rates were 466% higher, hospitalization rates were 650% higher and death rates were 356% higher than Idaho’s fully vaccinated population.

From May through July, the rate of infection, hospitalization and death was many times higher than among the fully vaccinated
From May through July, the rate of infection, hospitalization and death was many times higher than among the fully vaccinated. (Screenshot from Idaho state COVID-19 dashboard)

Do the vaccines still work against delta?

Yes, says Forbing-Orr, “but more people are getting infected who are vaccinated, so we all need to take precautions.”

That’s one reason public health experts are recommending that even vaccinated people wear masks.

But the vast majority of Idaho’s 5,801 cases in July were among Idahoans who aren’t fully vaccinated. The “breakthrough cases” made up only 13% of those new infections. With about 38% of Idaho’s population fully vaccinated, that suggests the rate of breakthrough cases was much smaller than would be expected if the vaccines didn’t work.

Idahoans who have been infected by the coronavirus despite full vaccination also are much less likely to have severe illness or end up hospitalized, and they are unlikely to die.

“The vaccine is going to stack the odds in your favor. Period,” Forbing-Orr said.

What works better? Vaccination or recovering from COVID-19?

That’s one big question that researchers and health experts are trying to answer. Studies have shown that vaccines provide reliably higher protection against the virus, while “natural” immunity is unpredictable, sometimes producing antibodies too low to fight off a reinfection.

Epidemiologists have no doubt that reinfection is possible after someone recovers from COVID-19. It has been nearly a year since the first case of a COVID-19 reinfection was documented in the U.S..

One report published by the Centers for Disease Control and Prevention suggests vaccination offers two-fold protection compared with antibodies from the actual virus. Looking at cases in May and June in Kentucky, the report found that residents who weren’t vaccinated had 2.34 times the odds of reinfection compared with those who were fully vaccinated.

The state health department is tracking breakthrough infections, but hasn’t yet determined how many Idahoans were reinfected after recovering from COVID-19.

That’s because epidemiologists were still trying to define what qualified as a “reinfection.” Why? Researchers have found that some people harbor the virus, or traces of it, for much longer than a week or two. So, they may test positive weeks after their initial diagnosis. In addition, some people may have been symptomatic and diagnosed with the disease, but never got tested; if they test positive now, does that qualify as a reinfection?

The Council of State and Territorial epidemiologists recently (mid-June) adopted a national case definition for reinfections and we are now working on implementing that case definition with the data we have,” Dr. Kathryn Turner, state deputy epidemiologist, told the Sun.

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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.