People are unsure if it is best to keep calm and continue with their lives in the face of the delta plus variant.
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Oh no! It won't happen again.
A coronavirus variant has emerged just as the U.S. COVID surge has started to slow down. This time, it's in the U.K.
This mutant, also known as "delta+" in the media, is causing concern due to its spread across Britain in recent weeks. It is now responsible for approximately 6% of all cases in Britain.
NPR spoke to three people who have been closely following the variants since they first appeared last fall.
Question 1: The variant's name is delta-plus. What does "plus" stand for, if delta is already extremely contagious?
William Hanage, an epidemiologist at Harvard University, says that it is a little like Delta's grandchild.
It was first discovered in India last year. Since then, it has continued to evolve and acquire more mutations. These mutations have resulted in many variations of delta, some even here in the U.S.
Hanage claims that all these new versions of delta are descendants. "Delta+ has been interchangeably used for any descendant from delta that people are getting knickers in a twist around now. It is not clear if they should or shouldn't be twisting their knickers.
Hanage notes that all previous delta-plus mutants were not much different from the original delta in the past. They're not more dangerous or more transmissible.
Question 2: What about the new "delta plus", which is spreading across the U.K. It has been called "AY.4.2" by scientists. It now accounts for over 6% of all cases. Is that a sign it is more transmissible to the U.S. version of Delta?
"No one knows yet," says Jeremy Luban, a virologist at the University of Massachusetts Medical School. "It is too early to know."
Because there aren't enough data to measure its transmissibility yet, Luban says, "That being said, if it is less transmissible, it will likely be a small increase."
Hanage believes it is about 10% more transmissible that the original delta version.
Delta is already extremely contagious. The behavior of the variant won't be affected by a 10% increase in likelihood. If you increase the turbocharge 10%, your truck's supercharged engine will not be as powerful.
Question 3: However, there is still some increase in transmissibility. Delta-plus could sweep the U.S. and reverse this summer's lull in cases.
Luban states that there is no indication that the new variant will take off in the same way as the delta. I think if you asked people who follow these variants, they would all tell you that AY.4.2 is unlikely be a new Delta. It is unlikely that it will completely take over. It is more likely that there will be a gradual, incremental increase in the number of cases.
Justin Lessler, an epidemiologist at the University of North Carolina, has used computer models to predict what would happen if new variants arrive in the U.S. He ran a simulation using a variant that is 50% more transmissible to delta, and then looked at what the results were.
"Even with a variet that's much more transmissible then delta-plus cases didn't return to the types peaks last winter or the types we've seen during the delta wave," Lessler states.
He says that many Americans have some protection against SARS-CoV2 right now in the U.S. because they have immunity from infections, vaccines, or both. He says that it will take more than an increased transmissibility to reverse the current lull in America.
Lessler says that if there is a variant that can escape detection by antibodies, we might see a huge resurgence. There is no evidence to suggest that delta-plus may have this ability.
