Despite Stratus Surge, UK’s Covid Cases Don’t Match Early Predictions

Ever since the Stratus Covid variant, officially known as XFG, started spreading rapidly across the UK in April, scientists have been on edge, fearing a new wave. While Stratus has become the dominant strain, the increase in infections hasn’t been as high as many experts predicted. This doesn’t mean cases didn’t rise – they did, but the surge was far smaller than anticipated.

The Stratus variant has largely replaced other variants, keeping the overall Covid numbers steady when they might have otherwise dropped. But the latest data from the UK Health Security Agency (UKHSA) suggests that the long-anticipated “summer” wave might finally be upon us, reported the Independent.

The data shows that the percentage of hospital patients with respiratory symptoms who tested positive for Covid jumped by 22% in just over a week, from 7.2% on August 6 to 8.8% by August 15.

In less than three weeks, this figure had risen by 44%. The positivity rate is now four times higher than it was in early January, though still less than half of last year’s peak in July.

As schools are set to reopen, often after international travel, there’s concern that the rise in cases might continue, potentially leading to a full-on wave of increased transmission.

The cooler weather will only add to the pressure as more people move indoors, often to poorly-ventilated spaces, which makes it easier for the virus to spread.

It’s important to note that the positivity rate is based on hospital patients with respiratory symptoms, so it’s higher than the overall rate in the population. Since there is no wide-scale surveillance during the summer months, these figures from the UKHSA are our best clue about the current trend, according to scientists.

Bob Hawkins, a data scientist working with Independent Sage, explains that while test positivity rates don’t directly measure infections in the general public, they are still a useful indicator of overall infection trends.

He points out that these rates match trends observed in winter surveillance data, suggesting the UKHSA figures are a reliable (if rough) sign of what’s happening across the country.

Experts say the rise in infections can be attributed to a combination of factors, including waning immunity from both vaccines and previous infections. The XFG variant is also more contagious than previous strains and may be better at evading vaccines developed for earlier variants. That said, the latest vaccine is still providing strong protection, especially against severe illness.

There are concerns that the government’s decision to offer the autumn booster to 13 million fewer people this year – including pregnant women and those with heart conditions – could contribute to even higher case numbers.

The decision was based on advice from the Joint Committee on Vaccination and Immunisation (JCVI), which monitors emerging Covid data. However, many scientists disagree with this move, suggesting it could be a mistake.

So, while we may not be in a full-blown wave just yet, the recent data, combined with declining immunity, the “back to school” rush, and the cooler weather, strongly suggest that a new wave may be just around the corner.