“Delta plus” may sound like a new streaming service or an upgrade to extra legroom on a domestic flight.
If only it was so simple. "Delta plus" is a sublineage of the highly contagious coronavirus delta variant, which is storming across the county and causing COVID-19 case numbers to climb.
The name itself – "delta plus" – suggests the variant underwent an upgrade to become more virulent. But while little is known about the sublineage and its mutations, health experts say it’s not spreading efficiently now in the U.S., and Americans shouldn’t add it to their pandemic worry list.
“It’s a cool name that’s trending,” said Dr. Daniel Rhoads, section head of microbiology at the Cleveland Clinic. “When someone says 'delta plus' or any of these new names, it means the virus is continuing to evolve with us,” but there’s no evidence to suggest the new sublineage should be concerning.
He said the coronavirus added a few mutations to the original delta variant to create the "delta plus" strain, classified by scientists as AY.1. It initially rang alarm bells because it contained the K417N mutation, which affects the virus's spike protein.
Most of the COVID-19 vaccines, and all the ones authorized in the U.S., use the spike protein to the trigger the body’s immune system. The body creates antibodies that recognize the spiked protein on the coronavirus should it ever enter the body and attack.
“We don’t know exactly what (the mutation) does, but we know the spike protein is a key part of the virus because that’s primarily what it responds to when we make antibodies,” Rhoads said.
Another sublineage of the delta variant, AY.2, also contains the mutation. Theoretically, a mutation to the spike protein can affect how the vaccines work and provide overall protection against the coronavirus.
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So far, the “delta plus” variant seems to be all bark and no bite. The AY.1 and AY.2 sublineages have had plenty of opportunities to spread as the Centers for Disease Control and Prevention reports the delta variant makes up more than 90% of sequenced coronavirus cases in the U.S., but it hasn’t gained any momentum.
“If something has a bunch of mutations but it doesn’t start taking off, then it is by definition not a problem,” said William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health. “Everyone is obsessed with vaccine escape (mutations). What’s more worrying is how quickly it transmits and spreads. When you look at AY.1 and AY.2, they’re a small fraction (of delta cases), and they’re not increasing either.”
The AY.1 and AY.2 sublineages accounted for only .1% and .8% of delta cases, respectively, from July 18 to 31, according to the CDC. To compare, another sublineage of the delta variant called AY.3 made up 9.1% of cases.
Hanage and other health experts are more interested in the B.1.621 variant, first identified in Colombia, which remains unnamed but is gaining ground quickly in Florida, where a surge is devastating its unvaccinated residents.
The state accounts for one-third of all coronavirus cases in the country, reporting 110,477 cases for the week ending July 29 and 11,515 hospitalizations as of Tuesday, according to data from the U.S. Department of Health and Human Services.
Although health experts aren’t concerned about the delta plus variant yet, they say continuous transmission gives the virus leeway to potentially create a variant that’s more contagious and dangerous. Americans can help avoid that by getting vaccinated and wearing masks in areas of high or substantial transmission to stymie spread.
“The virus mutates more or less randomly, and most mutations are detrimental to the virus and actually make it less effective,” Rhoads said. “But the more times you give the virus a chance to roll the dice, the more opportunities it has to get it right.”
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
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This article originally appeared on USA TODAY: COVID ‘delta plus’ variant: Why experts say you shouldn’t worry, yet