The most up to date 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 vaccines less effective than they were against Delta, reports Independent.
Emergency measures
The more contagious Omicron Covid variant is spreading rapidly across the UK and is set to become the dominant strain in the UK. So far more than deaths from the new variant have been recorded and tens of thousands of infections logged.
Fears over Omicron prompted London mayor Sadiq Khan to declare a major incident in the capital in December and the NHS returned to its highest level of emergency preparedness, level four national incident, meaning that the health service’s response will be coordinated as a national effort, rather than led by individual trusts.
Announcing his “Plan B” restrictions in December, 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?
However, 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, with the World Health Organisation suggesting that “current vaccines remain effective against severe disease and death”.
Another preliminary study from the Africa Health Research Institute in South Africa, which was released on Tuesday 7 December, 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”, adding: “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 Omicron 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 December, 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.
On the same subject, 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.”
Meanwhile, Moderna’s chief medical officer, Dr Paul Burton, said previously that it would take three months for his company to produce a vaccine specifically targeting Omicron.
Johnson & Johnson was 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 was at that point unable to give a concrete timeline for vaccine development.
AstraZeneca has not revealed whether or not it will need to develop a new vaccine against Omicron.
However, 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.
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.
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Source: Independent
