Cause for optimism on weaker Omicron wave, scientists say


The days are getting longer, the dark is receding. So too shall our wintry night of Omicron pass. However much the pandemic feels endless, with each variant we get closer to the end and nearer to normality. As the data comes in from Omicron there are also, scientists believe, increasing reasons to be optimistic.

At the end of November there were barely 5,000 cases a day in London. By Christmas this had reached 30,000.

Despite a continued rise in cases in the elderly in London, hospital admissions have not risen in recent days. Strikingly, far fewer patients require intensive care, with numbers in London ICUs largely flat and far lower than last year. Boris Johnson’s spokesman said yesterday that although overall hospital admissions were increasing, “we’re not seeing that same jump in beds requiring ventilation, which is pleasing, and almost certainly a function of both the nature of Omicron and our successful booster programme”.

One of the oddities of Omicron is that the protection it gives is backwards compatible. While Omicron is able to easily infect people with immunity to Delta, studies suggest the reverse is not the case. “For some reason which is not entirely clear, the cross-immunity between Delta and Omicron doesn’t seem to be completely symmetric,” Francois Balloux, from UCL, said.

This is excellent news. Alpha may have pushed out the Wuhan strain, and Delta pushed out Alpha — but it was never inevitable that Omicron would supplant Delta. Unlike variants that came before, its chief advantage was that it evaded prior immunity, raising the chance it could coexist with those strains that came before.

If it and Delta had different immunological niches, they could live beside each other — two pandemic waves superimpose, providing a steady supply of hospital admissions. Now it seems likely that thanks to the immunity given by Omicron, Delta is on the way out.

The risk of admission to hospital with Omicron is only a third of that with Delta, according to most recent estimates. Modelling for the government suggests this means the peak of NHS pressure will be a third of what it might otherwise have been, an enormous difference without which hospitals would be on the verge of being overwhelmed.

Coupled with this, vaccines are still doing a good job of stopping people becoming seriously ill. While two vaccine doses are largely ineffective in stopping infection with Omicron, three doses still offer 88 per cent protection against admission to hospital.

“There will be new variants after Omicron,” Sir Andrew Pollard, head of the Oxford Vaccine Group, said. “We don’t yet know how they’re going to behave.” But does Omicron give us a hint?

“We would be in a very good position if the cost to the virus of being able to spread in a highly immune population like ours is to have variants like Omicron, which provide mild disease.” Pollard said.