Doctors say more contagious COVID-19 delta variant expected to dominate in Utah

Utah National Guard Spc. Sam Sargent changes his top layer of gloves at a COVID-19 test site at the Utah State Fairpark in Salt Lake City on Monday, May 17, 2021.

Utah National Guard Spc. Sam Sargent changes his top layer of gloves at a COVID-19 test site at the Utah State Fairpark in Salt Lake City on Monday, May 17, 2021. (Annie Barker, Deseret News)

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SALT LAKE CITY — The highly contagious and potentially more virulent COVID-19 variant that was first detected in India could soon be responsible for the majority of Utah coronavirus cases, an Intermountain Healthcare infectious diseases physician warned Friday.

"Like many, many other locations around the world, we do expect that because it's more transmissible, the delta variant will outcompete the current strains," Dr. Brandon Webb told the Deseret News. "So in a lot of ways, what we're seeing here is not a surprise."

Already, the number of coronavirus cases in the state caused by the variant known as delta has jumped to 162. Utah public health officials said in May there had been 10 cases from the delta variant since it was first identified in the state a month earlier.

The delta variant, believed to have been brought to Utah by individuals who had traveled to India, still accounts for fewer infections than some other variants. There have been 2,656 cases from the alpha variant first detected in in the United Kingdom, and 1,017 cases combined from epsilon variants first detected in California.

But Webb said the delta variant is poised to dominate other strains of the virus here based on what's happened in the United Kingdom, where the alpha variant has been pushed aside by the delta variant. The delta variant is blamed for a 50% rise in coronavirus cases in Britain since May that prolonged pandemic restrictions there.

That means it's just a matter of time before the alpha variant is displaced in other countries, too. Utah's variant case counts are already likely low since they come from sequencing samples, a process that takes around two weeks.


The Utah Department of Health had not included details about the delta variant on the public data posted to until Wednesday, after the federal Centers for Disease Control and Prevention elevated it to a variant of concern, department spokeswoman Jenny Johnson said.

The reason the number of delta cases went from 42 to 162 so quickly is because of an update to the international database that categorizes the coronavirus variations that combined another lineage of the virus with the delta variant, Johnson said.

"Anytime a variant is circulating in a population, we are concerned about the potential for it to spread quickly or cause more severe illness, hospitalizations or death," she said, calling the delta variant about 40% to 60% more transmissible than the alpha variant.

"It's estimated that the delta variant is currently causing 6% to 10% of all infections in the U.S. and expected to become the dominant infection by fall among unvaccinated people," Johnson said. She said all of the COVID-19 vaccines approved for use in the United States are effective against the known variants.

Webb said it's still not clear just how dangerous the delta variant is.

"What we don't know yet is whether it is not only more contagious but also more virulent, or in other words, more capable of causing severe disease. We don't know that for sure yet," the doctor said. He said the Pfizer and Moderna vaccines are 88% effective against the delta variant for those who have received both doses.

And when it comes to preventing someone from becoming sick enough from the delta variant to require hospitalization, Webb said the two-dose vaccines are 96% effective. The single-dose Johnson & Johnson vaccine is likely only 60% effective against the delta variant but 90% effective in preventing hospitalization, he said.

The protection against the new variant offered by the vaccines should encourage more Utahns to get the shots, Webb said, and to make sure they get both doses of the Pfizer and Moderna vaccinations, since the level of protection nearly triples after the second and final dose.

Anyone 12 or older can be vaccinated against COVID-19. Currently, 41.7% of all Utahns are considered fully vaccinated, meaning it's been two weeks or more since their final dose, while 48.7% have received at least one dose.


Gov. Spencer Cox, who is continuing to talk with leaders of the Utah Legislature about offering state incentives for the shots, said Thursday Utah may fall short of his goal of 70% of the state's adults receiving at least one dose by July 4. Right now, that's just 63.5% of Utahns 16 and older.

Cox expressed frustration that more Utahns haven't been vaccinated, telling reporters at his monthly PBS Utah news conference that in recent weeks, he's talked with people whose loved ones have been hospitalized or even died because they didn't get the shots.

"It's very sad," the governor said, adding that the situation is "completely preventable. They didn't have to die. They don't have to be in the hospital. But they're dead now, and they're in the hospital now, because they refused to get vaccinated."

Webb said the symptoms of COVID-19 cases caused by the delta variant can seem like a bad cold at the start, with a runny nose, cough and malaise rather than the aches, fever, headache, diarrhea and sore throat more typically associated with the virus.

That makes it important for those who believe they may have a cold to self-isolate and be tested for COVID-19 even if they are vaccinated, the doctor said, to ensure they don't unknowingly spread the virus to someone who hasn't been vaccinated or is still medically vulnerable after the shots.

"The pandemic is not over," Webb said, advising Utahns that "being proactive rather than reactive, and taking precautions where appropriate, can help us stay ahead of some of these evolving issues in the pandemic and continue to build on the momentum we've gained."

It's very sad. (The situation is) completely preventable. They didn't have to die. They don't have to be in the hospital. But they're dead now, and they're in the hospital now, because they refused to get vaccinated.

–Utah Gov. Spencer Cox

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Lisa Riley Roche


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