The highly contagious delta variant, which was first identified in India, has led to a surge in infections in countries around the world. Now, scientists have discovered a new mutation of this variant, dubbed "delta plus."
Delta variant vs. 'delta plus'
According to the Los Angeles Times, the delta variant is believed to be about twice as transmissible as other coronavirus variants. The World Health Organization (WHO) labeled it a "variant of concern," and Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, has said that it is "currently the greatest threat in the U.S. to our attempt to eliminate Covid-19."
"Delta plus," which was identified in India, is a form of the delta variant that has acquired a mutation on the spike protein called K417N, CBNC reports.
According to Forbes, this same mutation is also present in the beta variant, which was first identified in South Africa and which research suggests may be less susceptible to some vaccines than the original coronavirus strain.
Infections with the "delta plus" virus have been reported in countries around the world, including almost 40 cases in the United Kingdom and 83 cases in the United States.
The Indian government has already labeled the delta plus mutation a "variant of concern." INSACOG, a consortium of 28 laboratories that are genome sequencing the coronavirus in India, told the country's Health Ministry the variant's characteristics may include "increased transmissibility, stronger binding to receptors of lung cells, and the potential reduction in monoclonal antibody response," CNBC reports.
What experts have to say about the 'delta plus' mutation
However, several virologists and epidemiologists said that while the mutation merits attention, more data is needed before definitive conclusions can be drawn about the delta plus variant's transmissibility and other characteristics.
"It has a good name," Benjamin Pinsky, director of the Clinical Virology Laboratory at Stanford University, said of the "delta plus" mutation. But he noted that there is not enough data to indicate that it is more dangerous than other identified coronavirus variants.
Chandrakant Lahariya, a physician-epidemiologist and expert in vaccines and health systems based in New Delhi, expressed a similar sentiment. "If we go by the currently available evidence, delta plus is not very different from delta variant," he said.
Lahariya added, "It is the same delta variant with one additional mutation. The only clinical difference, which we know till now, is that delta plus has some resistance to monoclonal antibody combination therapy. And that is not a major difference as the therapy itself is investigational and few are eligible for this treatment. "
"It sounds like just another variant that's no better, no worse, than the regular delta variant, and it's a little unclear why everybody's pushing on it," George Rutherford, an epidemiologist at the University of California-San Francisco, said. "I don't see that this is a big, big problem right now. I mean, it may get worked up; it may turn out to be a bigger problem. But there's certainly nothing that I'm seeing that gives me undue concern right now."
That said, Rutherford said it's understandable that people are concerned by a potentially more transmissible variant or mutation of the coronavirus. While an estimated 71% of the population might need to be immune to reach herd immunity against the original coronavirus strain, according to Rutherford, the threshold would increase to around 84% with more transmissible variants, such as the delta variant.
"I know it keeps on seeming like there's more and more, and so it's certainly understandable why people are like, 'Why doesn't it stop?'" Monica Gandhi, an infectious disease expert at UC-San Francisco, added.
Ultimately, she and other experts advised people to get vaccinated to help slow and stop transmission.
"Once you tamp down transmission, it really will stop accumulating these mutations," she said. "That is the reason why we want to, of course, have global vaccine equity: to stop transmission." (Lee, Forbes, 6/27; Lin/Money, Los Angeles Times, 6/28; Ellyatt, CNBC, 6/24)