While the highly contagious new Stratus variant is sweeping through the UK, there are fears the Covid wave could now materialise. Covid cases are still much lower than they have been for almost all of the time since the pandemic started. This is because, to a large extent, while infections from the Stratus variant – officially known as XFG – have soared in recent weeks, they have mostly just supplanted the other variants that are around. The data suggests the overall number of Covid cases (from all variants) has risen by about a fifth since mid April, when Stratus accounted for a small fraction of infections. It now accounts for most of them. (Photo: Andrew Milligan/PA).

Cases could rise

But cases in the UK remain well under half what they were during the waves last summer and autumn.

Divided on the figures

Published by the UK Health Security Agency (UKHSA) last Thursday, figures showed the proportion of people with Covid symptoms that tested positive for the virus increased by 9 per cent in the week to Sunday 13 July, from 5.6 per cent to 6.1 per cent. This figure is far higher than the infection rate but is seen as the best indicator of infection levels across the UK scientists use during the summer when surveillance of the virus is lower. However, some scientists are questioning how accurately it reflects trends among the general public – providing another reason not to become complacent about the threat of Covid. “XFG has replaced the other variants. But that is against a backdrop of all the other variants showing a steep decline. So overall infection rates are not that much changed and recently have even declined,” Professor Paul Hunter, of the University of East Anglia, told The i Paper. (Photo: Dinendra Haria/Getty).

Infection rates are flat, for now

“We have not really seen any wave so far this year and infection rates have been fairly flat. So currently XFG has probably prevented what would have been a much more dramatic decline in infections. As to the future, if XFG increases much above 50 per cent and is still increasing then we will probably see it pushing up cases later this month. Probably the hot summer weather has pushed transmission rates down so the impact of XFG was less than if it had appeared at the start of winter,” Professor Hunter added. (Photo: Matt Cardy/Getty).

Summer wave

Stratus saw its share of total UK infections shoot up from around 1 per cent to nearly 30 per cent in the six weeks to 1 June and to 60 per cent on 29 June – at which point the next most common variant (NB.1.8.1 or Nimbus) accounted for just 6 per cent of UK Covid infections. Scientists expect that Stratus’ share of cases has continued to shoot up this month and that it now accounts for the vast majority of Covid infections. (Photo: iStockphoto).

Likely to see an autumn spike

But while Stratus has not yet caused a wave, Professor Hunter says that does not mean it would not – especially when the weather cools and people spent more time together indoors, in often poorly ventilated rooms. “In previous years, we have usually seen infection rates increasing during the autumn and I think it is likely that we will see this again this year especially as spring and summer rates have been quite low,” he said. “If we do see a rise how much would be explained by seasonal factors and how much by XFG would be difficult to determine.” (Photo: Tang Ming Tung/ Getty).

No need to panic

Professor Lawrence Young, a virologist at Warwick University, agrees the relatively low levels of Covid this summer “doesn’t mean that we are out of the woods”. And he cautions that “the true extent of virus spread in the population is difficult to assess due to a significant reduction in testing for Covid infection”. Professor Steve Griffin, of Leeds University, meanwhile, points out that while although we have not seen a spike in cases we “have seen a steady increase in the past months, just not a dramatic wave". "I believe that there are also geographically distinct patches of high test positivity, but country-wide things level out,” he told The i Paper. (Photo: Betul Abali/Anadolu/Getty).

Reduced vaccine rate has consequences

“It’s important to remember that this doesn’t mean we’re not seeing infections, just that they’re neither increasing nor decreasing particularly fast. This again makes Covid a different scenario to influenza, RSV, or other seasonal viruses which have now all but disappeared since their winter waves. “There’s a consistent rate of hospitalisation and deaths due to Covid still, and the reduced vaccine uptake in vulnerable groups remains a concern. And there’s long Covid to consider.” (Photo: Danny Lawson/PA).