Variant of coronavirus in South Africa could escape vaccines

• COVID-19 vaccines may be less effective against a more infectious version of the coronavirus first discovered in South Africa.
• New research shows that the mutated strain can escape antibodies developed in response to vaccination or infection with the original version of the coronavirus.
• But Pfizer said it could update its plans to tackle new variants in just six weeks.
• Visit the Business Insider homepage for more stories.

At first, there was little evidence to suggest that COVID-19 vaccines would not work against the mutated, more infectious versions of the virus that have emerged in recent months.

But preliminary research published this week suggests that a variant of the coronavirus detected in South Africa in December may partially escape the defenses that vaccines build in our body’s immune system.

The research has not yet been peer reviewed, but it suggests that the variant, known as 501Y.V2, may escape antibodies developed in response to vaccination or infection with the original version of the virus. This may mean that existing vaccines will not provide as much protection and that people who were previously infected with the original version of the virus could be re-infected with the new strain.

Penny Moore, a researcher at the South African National Institute for Communicable Diseases and co-author of the new study, told a webinar Monday that compelling data shows 501.Y.V2 mutations to be “problematic “.

His group’s research found that in half of the samples studied in the lab, antibodies in the blood of people who had recovered from COVID-19 were unable to stop the variant.

“Based on Penny’s data, it’s likely the vaccine will be a little less effective, but we don’t know how much less effective,” said David Montefiori, a virologist at Duke University Medical Center who was not involved in the ‘study. CNN.

The variant can dodge our body’s defenses

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Antibodies are protective proteins that our immune system generates when it detects a foreign substance, or antigen, in the body. These proteins are generated during an infection, and this is what a vaccine causes the body to build in order to prevent disease.

In general, antibodies fight infection by learning to recognize a virus and signaling to the immune system that it needs to be destroyed. They do this by bonding with the invader until he is wiped out. But if one virus is different enough from others to evade the mechanisms of existing antibody search and destruction, it can continue to wreak havoc.

South African researchers investigated whether the antibodies developed in response to the original version of the coronavirus work to protect people from the new variant. They used blood samples from 44 patients who had recovered from COVID-19 before the 501.Y.V2 variant was detected.

Scientists exposed the blood to the new variant and found that the antibodies in half of the samples were powerless against the strain. The antibodies in the other half of the samples mounted a weakened response.

These results “may herald reduced efficacy” of existing vaccines, the team wrote. They also warned that people who contracted the original coronavirus may be at risk for new infections from variants such as 501.Y.V2.

Additionally, Moore’s group found that three types of monoclonal antibodies – lab-made antibodies designed to target the coronavirus – were ineffective against the variant. Doctors use monoclonal antibodies to treat patients; the Food and Drug Administration has authorized two of these treatments.

Juan Mabromata / AFP / Getty Images

Nonetheless, Moore said more data is needed to draw firm conclusions about how the variant interacts with antibodies inside the body, especially in people who have been vaccinated. The research also failed to examine other parts of the immune system, such as B cells, which play a critical role in the development of new antibodies.

Nathan Grubaugh, an epidemiologist at the Yale School of Public Health, said it was difficult to say how much lab tests actually translate into the body. A 90% reduction in protection in a lab test “can still mean full protection in a human,” he told Insider.

As the virus mutates, vaccines may need to evolve

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The 501Y.V2 variant has a particular mutation in its spike protein – the part that the virus uses to invade cells – that has been “shown to reduce antibody recognition” in people who have had an infection or history. vaccination, according to François Balloux, the director of the University College London Genetics Institute.

Other mutations in the spike protein contribute to the increased infectivity of 501.Y.V2, the South African researchers said. This could explain why the country has been hit so hard since November. Over the past two months, the number of new coronavirus cases per day in South Africa has quintupled from an average of 2,300 to 13,000. It reached a record high of nearly 22,000 cases on January 8, and the country’s positivity test rate doubled in December. By the end of 2020, 501.Y.V2 had replaced almost all other versions of the coronavirus in South Africa.

It has spread to at least 20 countries.

Other variants like the one found in the UK have similar mutations in their spike protein. But a preliminary study by Pfizer-BioNTech found that the company’s coronavirus vaccine is effective against this variant.

Jesse Bloom, a biochemist at the Fred Hutch Institute in Seattle, said in a statement he was “optimistic that the current vaccines will continue to be very useful,” although he added that as the coronavirus continues to grow. ‘evolve, “it may be necessary to update vaccines.”

Updated vaccine could be ‘quickly deployed’

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All viruses mutate. Most mutations are harmless, but sometimes one emerges that undermines the immunity people have gained from a previous vaccination or infection. The flu, for example, mutates quickly, which is why we have to get vaccinated every year and why flu shots are not 100% effective.

The coronavirus mutates more slowly than the flu. That’s why Trevor Bedford, virologist at Fred Hutch, predicted in April that “it will take a few years for the virus to mutate enough to significantly hamper a vaccine.” But Bedford did not know at the time how much the virus would proliferate and how much the number of cases would increase; the more chances a virus has to spread (and therefore to replicate), the more likely mutations are.

Wednesday, Bedford tweeted that “the emerging situation can be addressed with an upcoming vaccine update”.

Pfizer’s partner BioNTech said it could produce a new vaccine for a variant of COVID-19 in about six weeks. Moderna’s medical director Tal Zaks said his company’s process would be swift as well.

“I think our technology is very well suited to rapidly deploy a vaccine based on the new variant,” Zaks said in a recent presentation at the JP Morgan Healthcare Conference.

This is because these mRNA vaccines do not contain dead versions of the virus, but rather genetic instructions that allow the body to internally make one of the virus’s signature proteins, thereby triggering an immune response. Adjusting these instructions is an easy change.

The decision to approve a modified vaccine would then rest with regulators.

Immunity to a virus is not all or nothing

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Even though the variant reduces the effectiveness of current vaccines, that doesn’t mean protection against infections wears off completely, experts say.

“We often talk about immunity as an all-or-nothing kind of thing, but it’s not,” Jennie Lavine, postdoctoral researcher in biology at Emory University, told Insider.

The ideal level of protection is sterilization of immunity – when “we have such good immunity in all the right places that the virus can’t even replicate if it gets in,” Lavine said.

But there’s a lot of common ground between that and zero immunity. For example, Lavine said, “the virus might be able to reproduce itself, maybe cause mild illness, maybe spread for a day or two instead of five or six days.”

She added: “The chances that the new variant will take us from sterilizing immunity to no immunity are really unlikely.”

It also helps that existing vaccines are very effective against the original virus.

“The Pfizer and Moderna vaccines are 95% effective – that’s an extraordinary level of effectiveness,” Montefiori told CNN. “If it cuts down to 90, 80, 70 percent efficiency, it’s still very, very good and likely to have a major impact on the pandemic.”

Catherine Schuster-Bruce and Aria Bendix contributed reporting for this story.