On January 15, US public health officials warned that a more contagious version of the coronavirus, which causes Kovid-19, may dominate the infection in the United States by March. That severe warning is referred to as B.1.1.7, a variant that was first identified in the United Kingdom.
But now, a week later, scientists are increasingly concerned about another version that has surfaced in South Africa.
There is evidence from several small, and not-yet-peer-reviewed, mutations in the South Africa version – known as 501Y.V2 and already present in at least 23 countries – in people with Kovid-19 again. There may be a greater risk of construction. Those who are already ill and still have some immunity to the disease.
Scientists have not confirmed that this variant is more contagious, although evidence is pointing in this direction. They are also concerned that 501Y.V2 may have implications for the treatment of Kovid-19. Resenarone, a company that has developed a cocktail of two monoclonal antibodies for patients with the disease, reported that 501Y.V2 may be able to excrete antibodies from one of its mixtures. The drug is still effective, but subsequent mutations may render it less frequent.
But perhaps most dangerous is the possibility that mutations in the variant may limit the effectiveness of existing vaccines, which is one of the best means to control the epidemic we have.
The results of these recent studies are “a serious indication that we’ll have to see how well vaccines can work,” Penny Moore, a virologist at the National Institute for Communicable Diseases in South Africa, told Vox. Together, they highlight the dangers of allowing Kovid-19 to spread uncontrollably and also illustrate the challenges that lay ahead to develop as viruses.
What can the 501Y.V2 Coronavirus version mean for Kovid-19 vaccines?
Moore is the lead author of a recent study on 501Y.V2 on Tuesday as an imprint on BioSixive. In South Africa, he and his team took blood plasma samples from 44 people who were infected with coronovirus during the first wave of infection in the country last summer and then checked how their existing antibodies, along with 501Y.V2, Responds to older variants.
Researchers sorted plasma samples into categories – high and low antibody concentrations. Although antibodies may worsen after infection, this does not mean that the protection fades completely. Another recent study showed that immunity from infection persists for at least five months in most people, so the antibodies in those who had the virus should still shield against earlier versions of the virus if one were re-infected. is.
In 21 cases – about half – the existing antibodies were powerless against the new variant when exposed in test tubes. This was particularly true for plasma from people who had mild previous infection, and a lower level of antibody, to begin with.
The findings suggest that a prior Kovid-19 infection may not help individuals overcome the new variant if they are exposed, especially if their earlier case was mild or symptom-free.
For scientist Trevor Bedford of the Fred Hutch Cancer Research Center, who was not involved in the research, the study also came as a possible warning sign about vaccines. Earlier this year, manufacturers may have to start revamping their shots to respond to changes in the virus’s genetic code, they wrote on:
501Y.V2 is still largely confined to South Africa, but it (or other antigenically drifted variants) may spread more widely in the coming months. I am planning this possible “stress” update for the fall of 2021. 9/10
– Trevor Bedford (@trvrb) 20 January 2021
Specific mutation scientists are most concerned with
The 501Y.V2 variant specifically carries a mutation of concern, known as E484K. This change is manifested in part of the virus, the spike protein, which fits into the receptor in human cells. Spike proteins are also major targets for currently available mRNA vaccines from Pfizer / BioNTech and Moderna.
“This mutation sits right in the middle of a hotspot in the spike,” Moore said. And it has become notorious among virologists for its ability to extract coronovirus antibodies.
Scientists have demonstrated how this can happen in other cell culture experiments. In the recently published Biorexive Preference, researchers from Washington State tracked how the mutation altered the effectiveness of the antibody response in 11 people’s convincing plasma – and also found that the E484K had a particularly powerful antibody evasion capability .
Other types of anxiety also carry the E484K mutation, with the first identification in Manaus, Brazil, known as P.1. And a case study suggests that re-construction may be possible in some people when exposed to the new version.
In an impression, researchers in Brazil documented a case of a 45-year-old Kovid-19 patient with no co-morbidities, who was rearranged with the new version months after her first bout with the disease. The patient experienced a more severe illness for the second time. Although this is limited evidence, it “may have major implications for public health policies, surveillance and vaccination strategies,” the authors wrote.
The broader context of the study also relates: More than three-quarters of the population in Manaus was estimated to have been infected with the virus during a spring hike, with cases coming up again and hospitals filling up. Researchers suspect the reinvention of the new variant.
“The news is not at all serious”
But “the news is not at all serious,” said evolutionary virologist Stephen Goldstein of the University of Utah. A prior indication, led by Rockefeller University scientists, suggested antibodies to the vaccine may be more potent than antibodies from previous infections. The researchers tested blood samples from 14 people who received the modern vaccine and six who were immunized with the Pfizer / Bayonet vaccine. Researchers found that the E484K mutation, and two others found in South Africa, were associated with a “small but significant” decline in antibody activity.
Nevertheless, Goldstein said, the vaccine-induced antibody “is so high that it is still extremely powerful against serum mutants.”
Moore said that to fully understand the risk of vaccine mutations, we would need clinical trials, including those vaccinated. “These studies symbolize a problem,” he said, “but how it translates into real life, we cannot tell.”
Goldstein said that immune responses also vary greatly among people. In a Washington paper, researchers found “widespread person-to-person variation” in how mutations affected a person’s antibody response.
“The bottom line is cause for concern about low efficacy, but efficacy will not fall below a cliff,” Goldstein said. “Vaccines are incredibly powerful. … if [they go] From 95% [efficacy] At 85% or slightly lower, we are still in great shape. That is why researchers and public health officials are strongly advocating for vaccination at the earliest.
Nevertheless, Moore warned: “From the standpoint of immune avoidance, variants first found in Brazil and South Africa are a concern, but this is just the beginning. This is our first indication that this virus can and does change. “
It is possible that even as we learn more, even E484K mutations will not turn out to reduce vaccines. But there may be other changes to the virus or developing there that will survive vaccine-induced antibodies as well. “Many people are infected now that it’s an arm race – the virus is now given every chance to mutate,” Moore said, so it can step into pathways that can easily escape immunity. ”