Are vaccines capable of counteracting Omicron?

Are vaccines capable of countering the "Omicron" strain of coronavirus?

Why do some scientists fear its ineffectiveness?

Does the third dose of the vaccine protect against Omicron?

Are current vaccines able to counteract the Omicron strain?

Scientists need more time to be sure;

"What we don't know yet is how contagious it will be, how successful our vaccines will be, and if it will cause more severe disease," said Rochelle Walensky, director of the US Centers for Disease Control and Prevention, doctor and scientist, on Sunday.

She said, "We actually hope that our vaccines will succeed, as if they do not succeed in preventing the disease completely, they prevent infection completely, as they can work to prevent exposure to severe disease and prevent people from needing to enter hospitals."

On the program “This Week” on the American television network ABC, Walensky stressed that the more mutations a strain is, the greater the need for more immunity to prevent infection, adding, “We are actually vaccinating more and more individuals with booster doses.” ".

"We know that the virus has many mutations, and many of these mutations are linked to more contagious strains," she said.

Experts say the next few weeks are crucial to understanding whether the Omicron strain is particularly dangerous, and whether it responds to current vaccines.

A study of epidemiological data in South Africa revealed that the risk of re-infection with the new strain of the Corona virus, Omicron, is 3 times greater than that of other mutated strains of Corona, according to what Bloomberg Agency reported Thursday, citing a statement via e-mail to the South African Center for Epidemiological Diseases and Analysis. The National Center for Infectious Diseases.

Bloomberg quoted study authors: Juliet Pulliam and Harry Moultrie as saying that the results demonstrated epidemiological evidence of Omicron's ability to evade acquired immunity from previous infections.

"I think there is a high probability that we will see a decrease in the effectiveness of vaccines," said Stephen Hogue, president of Moderna, in a statement to the American "ABC" television.

He added, "What I do not know is the level" of the decline, and he wondered: "Will it be like what we witnessed with Delta, against which the vaccines remained effective, or will we see a decrease in effectiveness by about 50%, which will mean that we have to modify the vaccines?"

Moderna, like other pharmaceutical companies, including Pfizer, has already begun working on adapting its vaccine if necessary.

Last Friday, the Director of Emergencies at the World Health Organization, Mike Ryan, said that there was no evidence to support the idea of ​​​​changing Covid-19 vaccines to be suitable for resistance to the Omicron strain.

And Ryan added - during an event reported by social networking sites - that despite that - and if necessary - work is already underway in the event that Omicron vaccines are needed.

"Right now we have very effective vaccines," Ryan said. "We need to focus on distributing them more equitably. We need to focus on getting the most at-risk groups vaccinated."

The head of the German company BioNTech, Ugur Sahin, said - at the Reuters Next conference - last Friday that his company may be able to modify its vaccine against the Corona virus relatively quickly to combat the new mutant Omicron.

He also added that vaccines will continue to provide protection from severe symptoms of the disease despite the mutations.

Biotech, in cooperation with Pfizer, produced one of the first vaccines against COVID-19.

"This strain may be able to infect the vaccinated. We expect that those who have received the vaccine will be protected from severe symptoms of the disease," he added.

He pointed out that the mutations of the virus mean that vaccinations are likely to become annual, as is the case with seasonal influenza.

Why do some fear that current corona vaccines will not be effective against Omicron?

The answer lies in a study published last September that predicted - in many ways - the emergence of a variant such as Omicron, that is, a variant with a very large number of mutations, and the study also provides important insights into the effectiveness of vaccines against Omicron, according to a report on the NPR website. (Npr).

In the study - published in the journal Nature - scientists were trying to understand how the coronavirus - whose scientific name is SARS CoV-2 - learns to outperform antibodies.

So scientist Paul Peñas and his colleagues engineered a super version of the virus that, although not the complete virus, was just a specific part of it.

They focused on the infamous part of the virus, the spike protein, which binds to human cells and is a target of important antibodies.

The researchers took about 20 mutations and put them all together into a single spike protein, which they call a "pleiotropic spike mutation."

These mutations have already appeared in many variants around the world, but not all of them together.

"It's the singular mutations that occur naturally and we've combined them," Benyas says.

It has been shown to help the virus avoid detection of antibodies.

Interestingly, Peñas says, the omicron variant contains many of the same mutations as this pleiotropic spiky protein, but he says it has more mutations. Instead of just 20 mutations on the spike protein, the omicron contains about 30.

Next, Peñas and his team took antibodies from people who had taken two doses of a messenger RNA (mRNA) vaccine - such as the Pfizer and Moderna vaccines - or had previously had Covid-19 infection, and tested these antibodies against the pleiotropic Spike protein.

"This pleiotropic protein was almost completely resistant to neutralizing antibodies in these two groups of plasma," Benias says.

"Based on these results, we expect that Omicron will be highly resistant to antibodies circulating in individuals who are convalescent or who have received mRNA vaccines, and it is clear that the magnitude of the loss of sensitivity to these antibodies must be experimentally determined."

 The image is not negative

"We remain cautiously optimistic that after 3 doses you will get some beneficial protection," says Pfizer's chief scientific advisor Dr. Michael Dolstein.

The hope is that protection against severe disease and hospitalization will continue, says virologist Jeremy Le Pen at U.M. Chan School of Medicine.

And Le Pen adds, "Antibodies are the primary tool your body uses to stop the initial infection with corona, but even if the effectiveness of your antibodies decreases by 10 or 20 times, that may still be enough to prevent you from going to the hospital."

In addition, there are other components of the immune system, such as T cells, that can clear an infection quickly if it occurs;

Thus helping to protect you from serious diseases In general, T cells are less likely to lose their effectiveness when the virus mutates.

For example, Dr. Antonio Bertoletti and his team at Duke NAS School of Medicine have preliminary data showing that T-cell activity is still very high even against a multicellular spike-like protein created by Peñas and colleagues.

"Bottom line: The picture doesn't look horrible for T cells," Bertoletti lab members wrote on Twitter.

Does the third dose of the Corona vaccine protect against Omicron?

Currently, boosters (the third vaccine dose) are the best defense against the new Omicron strain and the highly transmissible Delta strain, says White House chief medical adviser and epidemiologist and immunologist Anthony Fauci, according to an NBC report by Berkeley Lovelace Jr.

And Fauci said last Friday - in briefing the Covid-19 response team at the White House - that studies show that an additional dose of current Covid vaccines will increase levels of antibodies against all strains, adding, “There is every reason to believe that if you are vaccinated and boosted, you will at least get a degree Certain cross-protection (protection from another strain of virus), is very likely against severe disease, and even against an omicron variant.

Is it possible to use the same current vaccines?

Pfizer-Biontech, Moderna, and Johnson & Johnson are working on Omicron vaccines for use against the new variant if lab tests show a significant reduction in protection against severe disease, although it may take months before they are ready for distribution.

However, there is still debate among some health experts as to whether it is appropriate to use existing vaccines as boosters against new and emerging strains, as vaccines are still designed to target the original form of the virus that was identified in late 2019.

Dr. Paul Offit, a vaccine expert at Children's Hospital of Philadelphia, said the question is if you continue boosting with a vaccine that is primarily intended to mount an immune response against the ancestral strain (the original strain of the Corona virus), will that limit the body's ability to achieve an immune response to a virus that is very different from its predecessors. any omicron strain).

Offit describes a phenomenon that immunologists call "original antigenic sin," in which the body's immune system relies on the memory of its first encounter with a virus, sometimes resulting in a weaker immune response when it later encounters another version of the virus. virus.

Offit, who is also a member of the Food and Drug Administration's Vaccine Advisory Committee, said vaccines can activate this phenomenon as well, one example being the human papillomavirus.

Offit added that, in theory, it could apply to COVID-19 as well.

He said some experts have argued that it may be best for those who are not at risk of severe disease to wait for a booster dose until a specific option is available.

Offit, along with Philip Krause and Marion Gruber, former officials of the US Food and Drug Administration, wrote an op-ed published Monday in The Washington Post arguing that booster injections should be restricted to those at high risk of serious illness, such as older adults. Age and those who live or work in high-risk settings, such as health care workers.

They said the original two doses of the mRNA vaccines (Pfizer-Biontech and Moderna) still worked for most healthy adults.

Even if a boost with the original vaccine makes future vaccines less effective, it's not wise to wait for a specific variable dose to get a boost, said Elaine Foxman, an immunologist at Yale University.

She said that the end result is that there is a life-threatening virus that is still spreading throughout the country, and it has been proven that current vaccines protect against it.

Will the current shot be as good as it was against the original virus?

Maybe not, says Elaine, but it will at least provide some protection against it.

Are you receiving your Omicron Protection Booster Dose?

Answer Follow the vaccination guidelines in your country, if you direct the health authorities in your country to get the third dose you should receive it.

It is clear that booster doses of corona vaccines raise antibody levels, strengthen the body's defenses against infection, and may help offset any advantages that Omicron has gained through evolution.

Also, additional doses may at least slow spread, freeing up time for vaccine makers to develop an Omicron-specific formulation, if necessary.