The Omicron variant has the potential to “very substantially overwhelm the NHS” and cause up to 10,000 hospitalisations a day if it is as virulent as Delta, according to a leading scientist who helped shape Britain’s coronavirus lockdown strategy.
Prof Neil Ferguson, a mathematical epidemiologist from Imperial College London, said the UK was already experiencing a “very explosive wave of infection” from the new variant. This could lead to “quite an explosive wave of hospitalisations,” depending on the severity of disease caused by Omicron.
“Unfortunately, most of the projections we have right now are that the Omicron wave could very substantially overwhelm the NHS, getting up to peak levels of admissions of 10,000 people per day,” he told the Guardian.
Ferguson added that the figure could be reached “sometime in January” but noted the impact on deaths was less clear. He also added the caveat that the projection was based on assumptions around the variant’s ability to evade existing protection, and the premise that Omicron was similar to Delta in terms of the severity of disease it causes.
But Ferguson said: “Eeven the best case scenarios involve several-fold more admissions per day than we’re getting at the moment – we are at about 700 right now.”
The stark figure of 10,000 hospitalisations a day is more than double the current highest level, with 4,582 admissions on 12 January this year.
Some have been quick to point to early signs that Omicron may cause more mild disease, including former prime minister Theresa May.
Ferguson said, at present, however, there was very little data on the severity of disease caused by the new variant, and that it was not necessarily the case that viruses evolved to cause less severe illness – such a situation only occurs if it favours their transmission. With Covid, as “99% of transmission occurs before anybody even gets to hospital,” the severity of disease is “a very minor selection pressure”.
While there was a “little bit of a hint” in UK data of a slightly higher rate of asymptomatic infection with Omicron, Ferguson said it was too soon to say if it was good news. “It could be confounded with many other things like vaccine status [or] reinfection,” he said. “So we’ll just have to wait and see.”
He cast doubt on the plan-B measures announced by the prime minister on Wednesdaybeing enough if his worst-case scenarios came true.
“In the context of Delta I think the government had a clear policy that hospitalisations were manageable, deaths were relatively low, and they did not want to restrict people’s freedoms any more than they had to. I think that calculus has now changed with Omicron,” said Ferguson.
Nevertheless, the measures could prove to be enough if Omicron turns out to cause much less severe disease than the Delta variant.
‘If it turns out, actually, it looks like hospital admissions may only peak at 2,000 to 3,000 a day, then it’s possible that something like plan B – maybe a little bit plan B plus – might be sufficient, given the government’s overall motivation to do the minimum possible to avoid the NHS being completely overwhelmed,” he said.
But if Omicron ends up even close to the severity of Delta models suggest things could be different. “In most of those scenarios, all I would say is plan B will not be enough to stop an overwhelming wave of hospitalisations.”
The hope, he added, was that the new measures would slow the spread of Omicron, potentially dropping its doubling time to four or five days. That may not sound like much, but Ferguson noted it could buy crucial time to get more booster vaccines into arms – and allow scientists to get a better understanding of the risk of people ending up in hospital.
Ferguson’s team produced modelling early in the pandemic that suggested the UK would suffer 500,000 Covid deaths – before the onset of vaccines or a lockdown. But the disaster scenarios often proffered in these models are averted due to changes in government policy.
Sometimes, however, the modelling just comes a cropper: in July, Ferguson said the final phase of unlocking in England would bring on 100,000 cases a day – a level that was never reached – while the peaks and troughs over the past few months have left experts sometimes scratching their heads.
“I think people have been over-interpreting the ups and downs, which have been going on really since mid July,” Ferguson said. “I made the unfortunate, overconfident prediction that we’d hit 100,000 cases, which I then later apologised for, but that was a very clear multi-week exponential growth.”
He added: “Since then what we’ve seen is occasional rises, occasional falls, partly coincident with relaxing measures, a lot with school holidays, and a lot with vaccine rollout. So we’ve had this gradual pattern of increasing contacts – it’s not like on ‘Freedom Day’ in July, everybody went back to normal.”
Ferguson said the booster programme was already making a difference, with significant drops seen in hospitalisations and deaths, while there is evidence it may even have had an impact on infection rates in some groups.
“But now, in a certain sense that progress is slightly moot given we now have a variant which has evolved specifically to not wipe out, but substantially evade that immunity we’ve built up in population,” he said.
“It really is essential in the next few weeks that we get as many boosters out as possible, particularly getting high coverage in the most vulnerable groups, but frankly, across the population.”
Source: Guardian
