Updated June 17, 2021 - 5:03 pm
The Delta variant — the latest coronavirus mutant to be federally classified as a “variant of concern” — now accounts for 10 percent of new cases in the U.S. and possibly twice that rate in Nevada, health officials say.
This week, the Centers for Disease Control and Prevention reclassified the variant first identified in India based on “mounting evidence” that it “spreads more easily and may cause more severe cases when compared to other variants,” including the U.K. strain now dominant in the U.S., agency representative Jade Fulce said.
The Delta variant, previously classified as a “variant of interest,” is estimated to account for 10 percent of new cases across the country, more in some regions, Fulce said in an email.
In Nevada, however, the variant accounted for 19 percent of the cases sequenced, or genetically analyzed, in the past 14 days at the state’s public health laboratory, though the figure may be skewed by the state’s low number of cases, the lab’s director said Wednesday.
“We are getting so little positive cases to sequence that we are afraid that our sampling has a less probable chance of being a true representation of the population,” said Mark Pandori, director of the Nevada State Public Health Laboratory at the University of Nevada, Reno, School of Medicine.
Delta could dominate
There is some laboratory evidence that vaccines are less effective against the Delta variant, also referred to as B.1.617.2, Pandori said in an email.
However, he noted that some data also suggests that vaccines are less effective with the U.K variant.
“Frankly, the vaccines seem to be keeping that variant in excellent check. So, based on that, I am optimistic until more data comes in to clarify this picture,” he said.
In the U.K., the rapid spread of the Delta variant has resulted in the postponement of lifting pandemic restrictions on June 21. However, UNLV epidemiologist Brian Labus said that the effectiveness of vaccines used in the U.S., coupled with more than half the population having received at least one dose, ought to keep the variant from reversing the downward trend in cases.
“Anytime you find a variant that spreads more easily, it’s going to be a bigger challenge to control,” said Labus, an assistant professor at UNLV’s School of Public Health. “But as long as it’s not a major difference in how easily it spreads, it’s not going to reverse everything that we’ve done” to tamp down cases.
“As long as the vaccine still works against it, we can control this variant, just like any of the others,” he said.
Still, he predicts that within six months, the Delta variant will become the dominant strain in the country as a result of the ease with which it spreads.
“This will be the dominant strain, and it will be the one that infects unvaccinated people and spreads more easily among them,” he said.
The future of the virus
Through genetic sequencing of a sampling of specimens from positive test results, 19 cases of the variant have been identified, including 10 in Clark County, Pandori said.
As long as the virus continues to spread, like all viruses, it will continue to mutate, potentially evolving in ways that make it more dangerous.
“Infectious diseases that are allowed to replicate in a community are in a constant mode of evolving, genetically,” Pandori said. “Rarely do they ‘leap’ to worrisome versions; they tend to ‘step’ there. I see this as a step, and not a leap,” he said of the Delta variant.
“It’s another reason that widespread vaccination is so important. Vaccination isn’t just about herd immunity to protect our health. It’s also about genetic warfare. It’s about us limiting the virus’ ability to take those ‘steps.’ Because it can only take those steps as long as it has human hosts in whom it can evolve.
“Limit that, and you not only protect health, you end the very future of this virus.”