After two winters of Covid anguish, one would be forgiven for viewing the shortening of days with a sense of trepidation. It would not be entirely misplaced.
According to data from the Office for National Statistics (ONS), about one in 70 people in the community in England – an estimated 766,500 individuals – had Covid in the week ending 14 September, up from 705,800 people, or one in 75, the week before.
It is the first time since late July that an increase had been seen in England. There was also a rise in Wales, although infection levels have dropped slightly in Northern Ireland and Scotland in the most recent week, after the latter showed a rise the week before.
An increase in cases has also been seen in UK data collected by the Zoe health study, while the latest NHS figures show a 17% increase in the number of Covid patients admitted to hospital in England – from 3,434 in the week ending 12 September to 4,015 in the week ending 19 September – with larger percentage rises in some regions.
Should Covid take off again, the outlook is for a bumpy ride. “With cases already rising, it looks like we are in for a bad October and it’s likely to be worse than the last wave,” said Prof Tim Spector, a scientific co-founder of Zoe.
A Covid wave this autumn had been expected. Waning immunity from vaccinations and previous infections, increased mixing indoors, a decline in testing, the return of children to school and students to university, and other shifts in behaviours can all push up infection rates.
There are also new variants. While Omicron has dominated in the UK since last winter, there are numerous sublineages. The BA.5 sub-variant is the most common, but experts are keeping their eyes on others including BA4.6, BF.7, BA.2.75.2 and BQ.1.1.
As Dr Thomas Peacock, of Imperial College London, points out, recent data suggest the latter two each account for less than 0.5% of Covid genetic sequences in the UK – but they are growing fast. “It’s entirely possible an autumn/winter wave is driven by a mixture of variants,” Peacock said.
Prof Tom Wenseleers, an evolutionary biologist at the Catholic University of Leuven in Belgium, said BA.2.75.2 and BQ1.1 have mutations in their spike protein that help them to partly escape from BA.5-induced immunity.
“Combined with the fact that Covid hospitalisations have already started rising again in the UK, and that the full effect of these variants still isn’t felt, I would say this is not such great news,” he said.
What is not known is the impact these variants may have on disease severity, although Peacock noted there were no indications at present that they cause worse illness. And Covid-related deaths remain low.
Wenseleers said: “Most scientists believe that our high population immunity will cause the infection fatality rate to keep on declining. But any new infection wave will of course add to the toll of the pandemic.”
But deaths are not the only concern. Peacock said: “Even a small wave is going to put massive additional strain on the health service, particularly if paired with other respiratory viruses making a comeback this winter,” such as flu.
Experts agree that vaccines are crucial in tackling Covid. “I can only recommend everyone that is offered a booster to go and get one: this is the best way to protect oneself from severe disease, and limit the impact of any new wave,” Wenseleers said.
Dr Emma Hodcroft, a molecular epidemiologist the University of Berne and the University of Geneva, said studies suggest the new dual-variant Covid booster shots available in the UK and other countries may increase protection against Covid, while Dr David Strain, of the University of Exeter’s medical school, said vaccination could also reduce the chance of developing long Covid.
But there are concerns over uptake. “We’re getting a whole host of vaccine fatigue – people are just getting fed up of being told to go and get their vaccine,” Strain said.
A new wave of Covid also poses the potential to disrupt education, transport, deliveries and other infrastructure, said Hodcroft, raising the question of whether further measures, such as masking or home working, may also be needed.
“In general, I think right now the most important thing is to look carefully at our plans for autumn and ensure that we do have a plan,” she said.