How does Ómicron respond to Pfizer, AstraZeneca and Moderna vaccines?



CORONAVIRUS-SOUTH AMERICA


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CORONAVIRUS-SOUTH AMERICA

The most recent variant of covid-19 has begun to spread in United Kingdom: The number of confirmed cases has almost doubled between Wednesday and Thursday.

A total of 817 cases of the omicron variant of covid-19 have been registered in this country, 249 on Thursday.

The first Minister Boris Johnson he said at his news conference on Wednesday that the doubling rate could be between two and three days because the variant is highly infectious.

Are vaccines effective against omicron?

Results of preliminary studies conducted by the German Center for Infection Research found that there were significant reductions in antibody potency of the Pfizer-BioNTech, Moderna, and Oxford-AstraZeneca vaccines against the omicron variant.

However, two doses of a vaccine should offer some protection against serious infections. The World Health Organization (WHO) suggests that “current vaccines remain effective against serious infections and death.”

Professor UÄ??ur Å??ahin, CEO and co-founder of BioNTech, said on Wednesday: “People who have received two doses are probably not significantly prevented from infection or any kind of disease. We know they will have memory T cells, which could prevent severe infections.”

At the first official briefing offered by vaccine manufacturers on how likely their products are to be effective against the omicron variant, Å??ahin mentioned that booster dose acceleration programs were “the right way forward”, and suggested that an extra dose seems to compensate for the lower compatibility of the vaccine to combat covid-19, compared to other previous variants of the virus.

A preliminary study from the Africa Health Research Institute in South Africa, published Tuesday, found that the potency of antibodies against the omicron variant was reduced 41-fold after two doses of Pfizer.

Although these results showed “much more extensive leakage,” the researchers noted that “prior infection, followed by vaccination or a booster dose, is likely to increase the level of neutralization and provide protection against severe infections of the omicron variant.”

Professor Alex Sigal, from the African Health Research Institute, commented on Twitter that the results were “better than I expected for the omicron”, adding: “The fact that you still need the ACE2 receptor and that the leak is incomplete means it is a manageable problem with the tools we have.”

Are some types of vaccines more effective than others?

A small study has suggested that the omicron variant could better evade the protection offered by the Pfizer/BioNtech vaccine than the initial covid-19 virus type.

There appears to be a “very large drop” in immunity against the new variant among those who received Pfizer doses, Sigal said, after his lab studied blood samples from 12 people who had received this vaccine.

Moderna has yet to release any official results on the efficacy of its omicron vaccine, but company president Stephen Hoge said it’s highly likely that current vaccines won’t hold up as well to the new variant.

On Sunday, Hoge told ABC News: “I think there is a real risk that we will see a decrease in the effectiveness of vaccines.

“What I don’t know is how substantial it is.”

Will a new omicron vaccine be launched?

Vaccine makers have said they will continue “full speed” with their plans to develop an updated vaccine based on this new variant, which should be available in March 2022 if needed.

Pfizer said last week that, if necessary, it could produce an omicron-adapted vaccine in “approximately 100 days.”

“We are continuing to work on a tailored vaccine that we believe will help induce a high level of protection against omicron-induced COVID-19, as well as prolonged protection compared to the current vaccine,” explained Professor Å??ahin.

Meanwhile, Moderna’s chief medical officer, Paul Burton, said last week that it would take three months for the company to produce a vaccine specifically targeted for the variant.

For its part, Johnson & Johnson is currently testing its omicron vaccine. The company’s global director of research and development, Mathai Mammen, said in a statement: “We have begun work to design and develop a new omicron vaccine and will move quickly into clinical studies if necessary.”

However, the company has not yet disclosed a timeline for the development of the vaccine.

AstraZeneca has not disclosed whether it will need to develop its own new omicron vaccine.

However, Oxford professor Sarah Gilbert, who helped create AstraZeneca’s current vaccine, mentioned that existing Covid-19 vaccines, no matter who makes them, are not likely to perform well against the variant.

“Until we know more, we have to be careful, and take steps to slow the spread of this new variant,” he told BBC Monday.

How many doses will we need?

Three doses of Pfizer-BioNTech are considered likely to protect against omicron variant infection, initial data from Pfizer’s lab have suggested, although this has not yet been peer-reviewed.

Two doses of the vaccine could prevent serious illness, but cannot be guaranteed to prevent people from getting COVID-19.

Pfizer CEO Albert Bourla suggested that a fourth dose might be needed for better protection against omicron.

Bourla explained for Squawk Box, from CNBC, that the company was waiting to see real data to decide if more doses will be required to combat omicron.

“When we see actual data, we will determine if the omicron is well covered by a third dose and for how long. And the second point, I think we will need a fourth dose,” he said.

He also stated that data could be expected in the next two weeks.

What are the symptoms of omicron?

Omicron often causes mild symptoms, so it can be hard to tell if it’s a cold or Covid-19.

Symptoms such as nasal congestion, headache and sore throat occur in both covid-19 and the common cold, making it very difficult to discern between the two without testing.

Professor Tim Spector, of the Britain’s Covid Zoe app, indicated that the data from the Zoe study indicates that around half of the cases of the delta variant are “missed”, as they do not present the “classic” symptoms of covid-19: fever, a new and persistent cough, and loss or change in the sense of taste or smell.

“Omicron is probably more, much more similar to the mild variants that we’re seeing in people who have been vaccinated with delta than anything else,” he explained.

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