How well will the COVID-19 vaccine work against the new strains? Experts weigh

COVID-19 variants have been in the headlines for weeks. But while officials have said the public shouldn’t be worried about the variants, they looked a little more worried over the weekend.

British Prime Minister Boris Johnson said during a recent press briefing that B.1.1.7, the COVID-19 variant that circulated in the UK and has spread to the US, “could be associated with a higher degree of mortality ”. Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, also said in an appearance on MSNBC that US officials were closely monitoring B.1.1.7, as well as the 501.V2 variant, aka. South. African variant.

Fauci said it was “a little more concerning” that the South African variant could negatively affect the monoclonal antibodies that have been given for treatment of the virus. “It looks like it decreases the effectiveness of the vaccine further, but we’re still in that cushion level of effective vaccines against them,” he said.

“These are serious situations that we are monitoring very closely and, if necessary, we will adapt to them,” Fauci continued. He also said vaccines could be changed in the future, if necessary. This new information raises a lot of questions about COVID-19 vaccines compared to variants. Here’s what you need to know.

First of all, it’s important to understand how COVID-19 vaccines work

Currently, there are two vaccines authorized in the United States against SARS-CoV-2, the virus that causes COVID-19: one from Pfizer-BioNTech and the other from Moderna. Both use a new technology called messenger RNA (mRNA).

These vaccines work by encoding part of the spike protein that is found on the surface of SARS-CoV-2, according to the Centers for Disease Control and Prevention (CDC). MRNA vaccines use pieces of this protein encoded by SARS-CoV-2 to create an immune response in your body, triggering it to create antibodies against SARS-CoV-2.

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After that, your body removes the protein and mRNA, but the antibodies remain. What is not clear at this point is the lifetime of the antibodies. However, they are expected to have the capacity to stay put, infectious disease specialist Dr Amesh A. Adalja, principal investigator at the Johns Hopkins Center for Health Security, told Yahoo Life.

How are the variants different from “regular” COVID-19?

There are currently several variants in circulation, but the two that are getting the most attention are the British strain (B.1.1.7) and the South African strain (501.V2). B.1.1.7 has several mutations in its genetic makeup, and some are in the spike protein of the virus, according to the CDC. Some of these mutations seem to make the virus more apt to cling to your cells than “normal” SARS-CoV-2, making this new strain more infectious, Dr. Thomas Russo, professor and head of infectious diseases at the ‘University of Buffalo, tells Yahoo Life.

The South African strain also has several mutations in its spike protein, according to the CDC. And, as a result, everything seems to spread more easily than regular SARS-CoV-2.

How effective are COVID-19 vaccines against variants?

As of now, they appear to be effective in preventing COVID-19 in people who have been vaccinated. Both vaccines are up to 95% effective against the traditional form of SARS-CoV-2. “It’s really good and a lot better than we expected at the start,” said Russo.

Since the appearance of variants in the UK and South Africa, Pfizer-BioNTech and Moderna have said their vaccines are effective against the new strains in lab tests.

“The Moderna COVID-19 vaccine expresses the full-length spike protein of the SARS-COV-2 virus, allowing the generation of neutralizing antibody responses to multiple domains of the protein,” Moderna explained in a press release in late December. “The full-length spike protein is 1,273 amino acids long, so although recent variants involve multiple mutations, for example up to eight amino acid changes in the spike protein of strain B.1.1. 7, these are less than one percent different from the spike protein encoded by Moderna’s vaccine. “

Moderna announced in a press release Monday that after testing its vaccine against the variants, there was “no significant impact” on the neutralizing titers – the concentration of antibodies in the body) – for B.1.1. 7. But, the company said, there was a six-fold reduction in neutralizing titers with the South African variant. Despite this reduction, Moderna says the neutralizing titers “remain above levels that should be protective”.

Nonetheless, Moderna announced that it had a strategy to “proactively fight the pandemic as the virus continues to evolve.” The company plans to test an additional booster dose of its vaccine to see if it will increase antibodies against emerging strains, as well as an emerging variant booster candidate to target the South African variant. “Moderna expects its mRNA-based booster vaccine to be able to further boost neutralizing titers in combination with all major candidate vaccines,” the company said in its press release.

What shall we do now?

From what is currently known, “the vaccines are likely to be effective against the variants. All the data shows that they will be effective, ”says Adalja. So far, research on the variants and vaccines has been done in the lab – not in humans – making it difficult to know for sure how much a drop in antibodies in a lab actually translates into the disease. real world, he said. “Vaccines don’t just induce one type of antibody,” says Adalja. “There is a whole host of antibodies, as well as T cell immunity to consider.” And all of this together can help prevent COVID-19, he says.

There’s also this to consider, according to Russo: There’s a decent amount of wiggle room, considering vaccines are 95% protective. “We can lose some efficacy from 95 percent, but even if the efficacy decreases, it is still likely that the virus is less severe and less likely to cause poor results in people who receive the vaccine,” says -he. “The unresolved question at this point is what will be our threshold of effectiveness to change the formulation and then produce the alternative vaccine? We are not there yet and it may never need to happen.

Dr David Cennimo, assistant professor of pediatric infectious disease medicine at Rutgers New Jersey Medical School, tells Yahoo Life it is “reassuring” to know that the antibodies in the vaccine “still bind well” to prevent COVID- 19. But, he adds, “I suspect they don’t bind as well as they would in a non-variable virus. That’s why they talk about the possibility of needing a different vaccine in the future. “

From that point on, Moderna explored a booster vaccine “just in case we needed it,” says Dr. William Schaffner, infectious disease specialist and professor at Vanderbilt University School of Medicine, to Yahoo Life. . “I hope not,” he adds.

Overall, people need to be convinced that the vaccine is “so far so good,” Schaffner says. “I don’t think we should be too enthusiastic about this,” he says. “Do we all get vaccinated now with the vaccine that is available when we can and, if we need a booster later, we will take care of it.”

For the latest news and updates on the coronavirus, follow to https://news.yahoo.com/coronavirus. According to experts, people over 60 and those with compromised immune systems continue to be at greatest risk. If you have any questions, please consult the CDC‘the sand WHO resource guides.

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