Tougher Covid restrictions may be needed to prevent Omicron causing anywhere between 25,000 to 75,000 deaths in England over the next five months, according to scientists advising the Government.
Experts from the London School of Hygiene & Tropical Medicine (LSHTM), who also sit on the Scientific Pandemic Influenza Group on Modelling (SPI-M) or the Scientific Advisory Group for Emergencies (Sage), used experimental data to look at how Omicron may transmit as the country heads into 2022, and predicted a large wave of infections in January.
Even under the most optimistic scenario (low immune escape of Omicron from vaccines and high effectiveness of booster jabs), a wave of infection is projected which could lead to a peak of more than 2,000 daily hospital admissions, with 175,000 hospital admissions and 24,700 deaths between December 1 this year and April 30, 2022.
The team predicted a peak of daily hospital admissions of 2,400 in January under the most optimistic scenario. At present, there are about 680 admissions per day.
In this optimistic scenario, bringing in control measures early in 2022 – such as restrictions on indoor hospitality, the closure of some entertainment venues and restrictions on how many people can gather in one place – would be sufficient to substantially control the wave, reducing hospital admissions by 53,000 and deaths by 7,600.
This could cause 492,000 hospital admissions and 74,800 deaths, according to the study, which has not yet been peer-reviewed.
In this scenario, the team estimates that stronger measures may be required to keep the peak number of hospital admissions below the January 2021 peak.
The London School of Hygiene scientists assumed Omicron causes the same severity of illness as Delta in the unvaccinated and those with no prior protection. They did not look at the impact of measures such as mass population testing to control its spread.
They said in their paper: “These results suggest that Omicron has the potential to cause substantial surges in cases, hospital admissions and deaths in populations with high levels of immunity, including England.
“The reintroduction of additional non-pharmaceutical interventions may be required to prevent hospital admissions exceeding the levels seen in England during the previous peak in winter 2020–2021.”
Dr Rosanna Barnard, from LSHTM’s Centre for the Mathematical Modelling of Infectious Diseases, who co-led the research, said: “More data over the next few weeks will strengthen our knowledge on Omicron and the consequences of this on transmission in England.
“However, these early projections help guide our understanding about potential futures in a rapidly-evolving situation.
“However, our most pessimistic scenario suggests that we may have to endure more stringent restrictions to ensure the NHS is not overwhelmed.
“Mask-wearing, social distancing and booster jabs are vital, but may not be enough.
“Nobody wants to endure another lockdown but last-resort measures may be required to protect health services if Omicron has a significant level of immune escape or otherwise increased transmissibility compared to Delta.
“It is crucial for decision-makers to consider the wider societal impact of these measures, not just the epidemiology.”
Dr Nick Davies from CMMID, who co-led the new study, said: “These are early estimates, but they do suggest that, overall, Omicron is outcompeting Delta rapidly by evading vaccines to a substantial degree.”
He told a briefing “the booster programme will substantially mitigate the impact of Omicron in England”.
Dr Davies added that it was difficult to predict the true level of protection offered by two doses of AstraZeneca and Pfizer, and urged people to get boosters.
He said the findings of the study were “worrying” but added that “lockdowns have a really devastating impact on people’s lives and livelihoods, especially leading up to Christmas” and those impacts had not been included in the modelling.
He added: “It’s the role of decision-makers to weigh up all these different outcomes and decide what is the best policy to pursue. We’re … focusing on the epidemiological side of the control measures.”
The scientists made assumptions about the levels of transmissibility and immune escape of Omicron using “S” gene target failure (SGTF) data from cases in England.
These are cases that are highly likely to be Omicron because the SGTF occurs with Omicron but not the Delta variant.
For the two immune escape scenarios considered, the team estimated the Omicron variant to be between 10% less transmissible than the Delta variant to 35% more transmissible than Delta.
Paul Hunter, professor in medicine at the University of East Anglia, said any model “is only as good as its assumptions”, adding that one key assumption in this model is that severity of disease outcomes for Omicron is the same as for Delta in unvaccinated people.
He said there is still “significant uncertainty” about the impact of Omicron, but the modelling will be refined as more data becomes available.
Meanwhile, the latest figures from the UK Health Security Agency show there have been an additional 633 confirmed cases of the Omicron variant reported across the UK, bringing the total number of confirmed cases to 1,898.
A breakdown of the data shows there have been a further 618 confirmed cases in England, 11 in Scotland, two in Wales and two in Northern Ireland.
Some experts have already said Omicron is more transmissible and many expect it to rapidly overtake Delta as the dominant variant.
Earlier, Eleanor Riley, a professor of immunology and infectious disease, said Omicron is spreading so fast that people are “very likely” to meet someone infected with the Covid-19 variant unless they are “living the life of a hermit”.
The University of Edinburgh academic also warned “a lot of people” could still end up in hospital even if the coronavirus mutation proves to provoke milder symptoms than the Delta variant.
Prof Riley told BBC Radio 4’s Today programme: “Omicron is spreading so quickly that, I think, unless you are living the life of a hermit, you are very likely to come across it in the next few weeks.
On Friday, analysis by the UK Health Security Agency (UKHSA) found that the AstraZeneca and Pfizer-BioNTech vaccines provided “much lower” levels of protection against symptomatic infection with Omicron compared to Delta.
But the UKHSA said a booster dose gives around 70% to 75% protection against symptomatic infection with Omicron, as they urged people to have their boosters.
No 10 has maintained there are “no plans” to go further with measures in England, amid reports that proposals are being drawn up for a Plan C, featuring even tougher rules.
A Government spokesperson said: “We continue to look closely at all of the emerging data.
“We’ve been clear throughout that vital vaccines and boosters are our best line of defence against this virus and that is why we are urging people to come forward as quickly as possible as they become eligible.
“Plan B remains a proportionate response based upon what we know, so we encourage everyone to follow the rules by wearing a face covering, working from home if you can, testing regularly and coming forward for your booster when called.”