What we know about how omicron responds to vaccines

What we know about how omicron responds to vaccines
New jabs to target latest strain could be produced by March 2022

Die omikron variant van Covid-19 has begun to spread in the Verenigde Koninkryk, met Boris Johnson warning of a “tidal wave” of infections hitting these shores if the public do not observe social restrictions and get their vaccine booster jabs as a matter of urgency.

Maandag, the UK confirmed the first death from the new variant globally while health secretary Sajid Javid estimated that the rate of omicron infections was already at around 200,000 per dag, with the strain expected to become dominant in London within 48 ure.

NHS Engeland meanwhile announced that it will return to its highest level of emergency preparedness, level four national incident, meaning that the NHS response to omicron will be coordinated as a national effort rather than led by individual trusts.

Confirmed Covid cases have since risen to 59,610 in the latest figures, with daily deaths up to 150.

Announcing his new “Plan B” social restrictions last Wednesday, the prime minister said that the variant’s infection rate could double every two-to-three days due to the fact that it is highly transmissible, hence the decision to make booster jabs available to all adults by the end of December.

Are vaccines effective against omicron?

The latest analysis by the UK government’s Health Security Agency indicates that two Covid jabs do not offer strong protection against symptomatic infection from the new variant, with the current suite of entstowwe less effective than they were against delta.

Egter, those who have received a booster jab remain up to 70 per cent protected, the agency found, underlining the importance of getting a third shot as soon as possible.

Earlier results from studies conducted by the German Centre for Infection Research likewise found that there were significant reductions in antibody potency for the Pfizer/BioNTech, Moderna and Oxford/AstraZeneca vaccines against omicron.

But two doses of a vaccine should still offer some protection from severe disease, met die Wêreldgesondheidsorganisasie suggesting that “current vaccines remain effective against severe disease and death”.

Professor Ugur Sahin, CEO and co-founder of BioNTech, said last week: “Individuals who have received two vaccines will most likely not have a significant prevention from infection or any type of disease. We know they will have memory T-cells, which may prevent severe disease.”

In the first official briefing from vaccine manufacturers on how likely their shots are to be effective against omicron, Professor Sahin said that accelerating booster programmes was “the right way to go” and suggested that an extra dose of a vaccine does appear to compensate for the vaccine being less well matched to combat Covid, compared to other earlier strains of the virus.

Another preliminary study from the Africa Health Research Institute in South Africa, which was released on Tuesday 7 Desember, found there was a 41-fold reduction in the potency of antibodies after two doses of Pfizer against omicron.

Although these results showed a “much more extensive escape”, the researchers wrote that “previous infection, followed by vaccination or booster is likely to increase the neutralisation level and likely confer protection from severe disease in omicron infection.”

Professor Alex Sigal, a professor at the Africa Health Research Institute, said on Twitter that the results were “better than I expected of omicron”, toevoeging: “The fact that it still needs the ACE2 receptor and that escape is incomplete means it’s a tractable problem with the tools [we have] got.”

Are some types of vaccine more effective than others?

A small study has suggested that the omicron coronavirus variant may be able to better evade the protection offered by the Pfizer/BioNTech vaccine than the initial Covid virus type.

There seems to be a “very large drop” in immunity against the new variant among those given Pfizer’s vaccine, said Professor Sigal after his laboratory studied the blood samples of 12 people who had been vaccinated with the jab.

Moderna is yet to publish any official results on the efficacy of its jab against omicron but president of the company, Dr Stephen Hoge, said there is a good chance current vaccines will not hold up as well against the variant.

Speaking to ABC News on 5 Desember, Dr Hoge said: “I think that there’s a real risk that we’re going to see a decrease in the effectiveness of the vaccines. What I don’t know is how substantial that is.

Will a new omicron vaccine be released?

Vaccine makers have said that they will continue “at full speed” with plans to develop an updated omicron-based vaccine, which should be available by March 2022 if needed.

Pfizer has said that if needed it could produce an omicron-tailored vaccine in “approximately 100 days”.

Oor dieselfde onderwerp, Professor Sahin said: “We continue to work on an adapted vaccine which, we believe, will help to induce a high level of protection against omicron-induced Covid-19 disease as well as a prolonged protection compared to the current vaccine.”

Intussen, Moderna’s chief medical officer, Dr Paul Burton, said last week that it would take three months for his company to produce a vaccine specifically targeting omicron.

Johnson & Johnson is currently testing its vaccine against omicron with Dr Mathai Mammen, the global head of research and development for the company, saying in a statement: “We have begun work to design and develop a new vaccine against omicron and will rapidly progress it into clinical studies if needed.”

The company is, egter, yet to give a timeline for vaccine development.

AstraZeneca has not revealed whether or not it will need to develop a new vaccine against omicron.

Egter, Professor Sarah Gilbert of Oxford University, who helped create AstraZeneca’s current jab, has said that existing coronavirus vaccinations, no matter who produced them, are not likely to perform well against omicron.

“Until we know more, we should be cautious, and take steps to slow down the spread of this new variant,”Vertel sy die BBC.

How many jabs will we need?

It is thought that three doses of the Pfizer/BioNTech vaccine are likely to protect against infection from the omicron variant, initial Pfizer laboratory data has suggested, although this is yet to be peer reviewed.

Two doses of the vaccine may prevent severe disease but cannot be guaranteed to prevent people from contracting Covid.

Albert Bourla, CEO of Pfizer, suggested that a fourth dose of the vaccine might be necessary for better protection against omicron.

Speaking on CNBC’s Squawk Box, Mr Bourla said the company was waiting to see real-world data to decide whether or not further doses would be required specifically to combat omicron.

“When we see real-world data, [ons] will determine if the omicron is well covered by the third dose and for how long. And the second point, I think we will need a fourth dose," hy het gesê.

He went on to suggest that data could be expected in the next two weeks.

What are the symptoms of omicron?

Omicron often causes mild symptoms so it may be difficult to tell whether or not you have Covid or just the common cold.

Symptoms, soos toe neus, sore head and sore throat are applicable to both Covid and colds, making it is very hard to tell the difference without taking a test.

Professor Tim Spector, van Brittanje se Covid Zoe-toepassing, said that data from a recent Zoe study suggests that about half of all cases of delta are being “missed” as they are not showing up with “classic” Covid symptoms of fever, nuwe en aanhoudende hoes en 'n verlies of verandering van reuk of smaak.

“Omicron is waarskynlik meer, baie meer soortgelyk aan die ligte variante wat ons sien by mense wat met delta ingeënt is as enigiets anders," hy het gesê.

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