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How contagious is the new variant?



Scientists are trying to figure out what role B.1.617, the variant found in India, will play in future waves of Covid-19. The trajectory of the option, whether it continues to spread at its current pace or slows down, will be clearer in the coming weeks.

Option B.1.617 is one of the factors driving the current crisis in India and neighboring Nepal. It may also be linked to the recent increase in unvaccinated cases in the United Kingdom.

The variant is thought to be more contagious than the original SARS-CoV-2 virus, but there is still no clear evidence that it causes more severe disease or more deaths. The same public health measures ̵

1; masks and social distancing – can prevent the spread of the virus variant, experts say. And although it may have some effect on vaccines, its mutations are unlikely to be enough to weaken protection against serious diseases, studies show.

Yet B.1.617, which was originally identified in October, is being closely monitored as it spreads around the world. It is now found in at least 44 countries, including the United States, where about 3% of sequenced samples are version B.1.617, according to the latest data from the Centers for Disease Control and Prevention.

Because of two mutation-related variants, the variant from India has received the dreaded nickname “double mutant,” an incorrect term that is “completely useless,” said Deepta Batacharya, an associate professor of immunobiology at the University of Arizona Medical College. In fact, all identified variants of concern – including B.1.1.7 from the United Kingdom, B.1.351 from South Africa and P.1 from Brazil – have one or more mutations, he said.

“It’s misleading to look like it’s significantly different from the other options we’ve already seen,” he said.

How contagious is it?

Currently, the most contagious form of coronavirus is B.1.117, which has been prevalent in Britain and Europe since the winter and now accounts for three-quarters of coronavirus infections in the United States

Last week, variant B.1.617, first discovered in India, was officially classified as a “concern of concern” by the World Health Organization, which described in detail in the report the variant and its three lines – versions that differ slightly in mutations in the protein. virus.

Early data suggest that one of the pedigree lines, B.1.617.2, which has been found most frequently in the United States and the United Kingdom, may be the lineage associated with the highest transmission. An expert advisory committee on the government of British Prime Minister Boris Johnson said during a press conference on May 13 that the option from India could be as much as 50 percent more transmitted than option B.1.1.7, which was first identified in the UK. necessary research, experts say.

Trevor Bedford, a professor of evolutionary biology at the Fred Hutchinson Cancer Research Center, said option B.1.617.2 appears to be ahead of the option in the United Kingdom in India.

Unlike some other variants of anxiety, the one from India had several key mutations, but not many others that initially affected it. But over the past week, he has noticed that a growing number of recently sequenced samples in India are with this new version, not the British version.

“When this option was first spotted weeks ago, I didn’t attribute it so much,” Bedford said. He said he at the time likened the jump in India to a large extent to other factors such as low vaccination rates and a lack of social distancing.

He called the observation “critical,” but because of other factors that play a role in the spread of the infection, he has so far accepted the data as “big grain.”

It is difficult to say exactly how this option will play out in the United States, which has declined in new cases in recent weeks. If the option becomes more dominant in some countries, it could put more pressure on communities to vaccinate people even faster to slow the spread.

Vaccines beat options

Bhattacharya, who lost two family members in India to Covid-19 in recent weeks, is not worried that changes to this particular option could make vaccines ineffective. Even if there are breakthrough infections among vaccinated people, they will be in better shape, he said.

“This option seems to have taken some things that make it more transmissible, and that’s definitely a problem,” he said.

He is concerned about increased transmission, as even a small amount can lead to an exponential spread and easily overwhelm health systems, especially in countries with poor vaccination rates.

Studies by researchers at Emory University show that antibodies generated by the vaccine may be less effective for B.1.617.1, one of the variant lines. The authors found a sevenfold reduction in the ability of antibodies to block the variant compared to the original virus for which the vaccine was primarily intended. In comparison, the authors found an approximately fourfold decrease in the ability of antibodies to block the South African variant. The Emory study has been published as a pre-press study, but has not yet been reviewed by other scientists or published in a scientific journal.

Despite the reduction, the authors suggest that vaccines will eventually work against the option.

The authors write that the experiment “suggests that the protective immunity from the mRNA vaccines tested here is likely to be maintained against variant B.1.617.1.”

Shane Croti, a virologist and professor at the Institute of Immunology in La Jolla, is optimistic that vaccines will eventually prove effective against this option in the real world, as well as in a laboratory study.

In a recent study in the New England Journal of Medicine, researchers in Qatar found that the Pfizer vaccine was 97 percent effective in preventing serious illness and death in patients infected with any form of coronavirus, including variants.

“The fact that there is real evidence that the Pfizer vaccine works very well against the South African variant is very likely that the Pfizer and Moderna vaccines will also be very effective against these new Indian variants,” said Croti.


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