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How different Covid vaccines will deal with new variants of the virus



New, more contagious variants of the coronavirus are being investigated in the United States, raising questions about whether Covid vaccines currently in use will provide protection against mutations.

Many more contagious variants are emerging around the world in the United Kingdom, South Africa and Brazil. Variants from New York and California have been identified in the United States.

So far, studies have shown that currently used vaccines can recognize emerging variants ̵

1; but they do not provide as much protection against these new strains. For example, the South African version reduces the protection of Pfizer-BioNTech antibodies by two-thirds, according to a February study. Moderna’s neutralizing antibodies dropped six times with the South African option.

(There are several reasons why antibodies generated after receiving a vaccine may recognize a variant but not fight it. The antibodies protect you by attaching to each individual protein spike on the surface of the coronavirus, which prevents it from If your variant produces many times more virus, the antibodies may not be able to attach to all these virus pieces as accurately or effectively.)

But accelerators and new versions of variant-targeted vaccines are already being studied.

The three vaccines, which are authorized by the Food and Drug Administration from Moderna, Pfizer-BioNTech and Johnson & Johnson, work in different ways and therefore have different approaches to handling variants. Here’s what we know:

Modern

Moderna is testing a third dose of its existing vaccine, as well as a booster that targets the South African variant. (He sent samples to the National Institutes of Health for clinical trials on February 24.)

Moderna CEO Stefan Bansel said the company “is committed to making as many updates to our vaccine as necessary until the pandemic is contained,” in a February 24 press release.

The Moderna vaccine uses messenger RNA or “mRNA” technology to deliver genetic material to cells with instructions on how to make a non-infectious piece of the coronavirus peak protein. The immune system recognizes copies of the thorn protein and makes antibodies against it. If a fully vaccinated person is exposed to the actual virus in the future, the body can remember how to elicit an immune response and make antibodies that fight the virus.

Boosters for new variants use the same technology as Moderna’s original Covid vaccine. Bancel said it was essentially a matter of “copying and pasting” the new mutations in the vaccine. Dr. Kizzmekia Corbett, who led the Moderna vaccine team, called this approach “plug and play.”

It can take months for clinical data to be ready for review, and even longer for boosters to be approved, manufactured, and ready for administration.

Moderna president Stephen Hoge told Scientific American that if options began to dominate infections in the coming months, the company was ready to “know when and how we will move.” Hoge did not comment on when the booster will be available.

Pfizer-BioNTech

Pfizer-BioNTech is also testing a third booster shot of its vaccine (which is an mRNA vaccine) on people who have been fully vaccinated in a phase 1 study. Participants will receive their third dose six to 12 months after they have been fully vaccinated. message.

The company is also discussing a clinical trial for a “variant-specific vaccine”, which is a reconstructed version of its original vaccine using a strain from South Africa, the statement said.

“We believe our vaccine is highly active against all strains,” Pfizer Chief Scientific Officer Michael Dolsten said in a February 25 interview. In the future, it’s a “reasonable opportunity” for people to need regular booster shots, Dolsten said. Or companies may need to change tensions every few years to adapt, he said.

Like Moderna, Pfizer’s mRNA vaccine is quite adaptive.

“The flexibility of our own mRNA vaccine platform allows us to develop technical booster vaccines within weeks if needed,” Ugur Sahin, CEO and co-founder of BioNTech, said in a statement.

“This regulatory pathway has already been established for other infectious diseases such as influenza. We are taking these steps to ensure long-term immunity against the virus and its variants.”

Johnson and Johnson

The latest vaccine, approved for emergency use by the Food and Drug Administration, is 72% effective in preventing moderate disease in the United States, but in South Africa, where a highly contagious mutation of the virus is the main option, the effectiveness is 64% effective. prevention of moderate to severe or critical Covid, according to FDA data. In Brazil, the vaccine was 66% effective.

(Experts say it’s worth noting that the Johnson & Johnson trials took place when the new variants had already become the dominant strains in South Africa and Brazil, while the Moderna and Pfizer trials were conducted before that happened. )

Johnson and Johnson’s single-dose vaccine uses adenovirus, a virus that causes the common cold, as a messenger to send instructions to the body’s cells.

In an interview with CNBC’s “Squawk Box”, Johnson & Johnson CEO Alex Gorski said the company is in a good position to adapt the vaccine to options and is working on developing software that will “help address some of these new and emerging options “. 1st March. He did not explain how the software would work.

“We are quite confident, based on the clinical data we already have with our vaccine, that we will see a very strong response, but at the same time we are doing exactly the same [as other companies working on variants], “Gorsky said.

Novavax

Although the Covid two-shot Covid vaccine has not yet been approved in the United States, the company expects to receive FDA approval by May.

Data from a study in the United Kingdom in January showed that the vaccine was over 89% effective against Covid and 85.6% effective against the British version. But the Novavax vaccine was less than 50% effective for the South African strain.

Novavax is working on a third booster that could be tested in April, a company spokesman told Scientific American.

Novavax is a two-dose “protein subunit vaccine”, which means that it contains harmless pieces of surface thorn protein that directly trigger the immune system. So essentially, scientists can add different strains to an existing vaccine when variants appear.

Novavax CEO Stanley Erk told NPR that Covid vaccines can be changed “very easily”, similar to the way the flu vaccine is changed every year to suit known strains.

It may even be a ‘bivalent vaccine’, which is a vaccine that protects against several strains of the virus. “So we will use the original Wuhan strain and the South African strain [to tweak the vaccine] and test it on humans, probably in the second quarter of this year, “Erk told NPR.

To check your eligibility status, you can use NBC News’s plan for your vaccine tool.

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