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(CNN) – A new and slightly modified version of the delta variant of the coronavirus is spreading in several countries, including the United Kingdom, the United States and India, health officials say.
This strain, which has generated a significant amount of global media attention, is called B.1.617.2,1 or AY.1, delta plus for short, and is a version of the delta variant first detected in India. in February.
It was first reported by Public Health England, a government health agency, on June 11. But the first UK cases were sequenced on April 26, suggesting that the variant may have been present and spreading in the spring.
The Indian government said it sent the variant to the Global Data System along with samples for genomic testing.
Some 200 cases have been detected in 11 countries. Health experts are investigating whether delta plus may be more transmissible than other strains such as the alpha or delta variants, but it is too early to say for sure what its effects may be.
Here’s what we know so far and the questions that remain unanswered.
How is delta plus different from the delta variant?
All variants carry groups of mutations. Delta plus has an additional mutation called K417N, which distinguishes it from the regular delta variant. This mutation affects the spike protein, the part of the virus that attaches itself to the cells it infects.
The K417N mutation is not entirely new: it has “arisen independently in several viral lineages,” said Francois Balloux, director of the Institute of Genetics at University College London (UCL).
The mutation was seen in a strain found in Qatar in March 2020, and is also found in the beta variant, which was first detected in South Africa last fall, he told the Science Media Center on Wednesday.
“The mutation may contribute to immune escape, although its impact on transmissibility is not well defined,” he added.
All viruses constantly mutate. Some of these changes cause viruses to infect cells better or reproduce better, while others have little effect or are even harmful to the virus.
To date, there have been about 160 strains of the coronavirus sequenced globally, Balloux said.
There are also “other delta plus variants with other mutations,” the Indian government said on Wednesday, adding that AY.1 was simply the best known.
Maria Van Kerkhove, technical leader of the World Health Organization on covid-19, added that the team was “looking at these specific mutations and what they mean in terms of transmission, in terms of severity and, what is really important: what what they mean in terms of our medical countermeasures. ‘
Meanwhile, the regular delta variant, also known as the B.1.617.2 strain, has spread rapidly. It has been reported in dozens of countries and is between 40% and 60% more transmissible than the alpha variant first identified in England, the European Center for Disease Prevention and Control (ECDC) said.
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Is it more infectious or deadly?
According to the government of India’s covid-19 genome sequencing body, the delta plus variant exhibits several worrisome traits, such as increased transmissibility, stronger binding to lung cell receptors, and a possible reduction in the response of antibodies.
It is not yet clear what effect the mutation may have on the efficacy of the vaccine, but Julian Tang, professor of respiratory sciences at the University of Leicester, warned that it could give the variant “significant vaccine escape properties.”
Most coronavirus vaccines are designed to train the body to recognize the spike protein, or parts of it, where the additional delta plus mutation is located.
However, there is still not enough evidence to determine anything conclusively and other experts have expressed caution. On Wednesday, the Indian government said the role of the mutation in “immune escape, disease severity or increased transmissibility, etc.” he is under continuous surveillance. ‘
For now, experts are largely warning people and governments to remain vigilant but calm.
Besides the beta variant, none of the other strains carrying the K417N mutation “have been particularly successful so far,” Balloux said. “It has been found in several countries, but it has remained extremely low … There is no evidence that the strain is currently spreading in any country.”
The WHO’s van Kerkhove said the organization was tracking delta plus to determine its transmissibility and severity.
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Where has it been found?
So far, delta plus has been reported in 11 countries, but the number of cases per country only reflects samples that have been sequenced and more data is needed to determine the actual rate of spread.
The United States has sequenced and confirmed the largest number of cases so far, with 83 cases as of June 16, according to Public Health England.
The UK is next, with 41 cases as of June 16. Improved contact tracing, testing and isolation has been implemented in areas where delta plus was reported, Downing Street confirmed Thursday.
The first cases sequenced in the UK were contacts of people who had traveled or transited through Nepal and Turkey, according to Public Health England.
India follows with 40 cases, the government said on Wednesday. The cases are distributed in three states: Maharashtra, Kerala and Madhya Pradesh. On Tuesday, the Indian Ministry of Health designated it as a “variant of concern” and put all three states on alert.
The government said the number of cases was still low, but urged states with cases to “improve their public health response” by intensifying testing, screening and priority vaccination.
The rest of the cases are distributed among Canada, India, Japan, Nepal, Poland, Portugal, Russia, Switzerland and Turkey.