The more contagious Omicron variant of Covid-19 is continuing to spread rapidly across the UK and could eventually become the dominant strain of the coronavirus.
So far more than 75 deaths from the new variant have been recorded and 246,780 infections logged.
Prime minister Boris Johnson has ruled out introducing new restrictions in England for the moment but has said his government “reserves the right” to implement measures in the coming weeks should the current high rate of infection begin to translate into mass hospitalisations that threaten to overwhelm the NHS.
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, 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 recent decision to make booster jabs available to all adults.
Are vaccines effective against Omicron?
The most up to date analysis by the UK 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.
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”.
Professor Ugur Sahin, CEO and co-founder of BioNTech, has said: “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 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 in 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.
Pfizer has said that if needed it could produce an Omicron-tailored vaccine in “approximately 100 days”.
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 the new variant 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.
“Until we know more, we should be cautious, and take steps to slow down the spread of this new variant,” she told the 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 the latest strain.
“When we see real-world data, [we] 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,” he said.
What are the symptoms of Omicron?
The new variant often causes mild symptoms so it may be difficult to tell whether or not you have Covid or just the common cold.
Symptoms, such as stuffy nose, 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, from Britain’s Covid ZOE app, 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, new and persistent cough and a loss or change of smell or taste.
“Omicron is probably more, much more similar to the mild variants we’re seeing in people who have been vaccinated with Delta than anything else,” he said.
