‘Frankenstein’ Covid variant rockets four-fold in just a month

A new Covid variant dubbed ‘Stratus’ has soared to dominance in the UK, with experts warning it could drive a wave of new infections.

Stratus—scientifically known as XFG—is thought to be more infectious than previous Covid strains due to mutations that help it evade the immune system. 

Now, data from the UK Health Security Agency (UKHSA), shows Stratus has now become the dominant Covid strain in England.

The variant has gone from accounting for about 10 per cent of all Covid cases in May to almost 40 per cent three weeks later in mid-June. 

Stratus—a descendent of the already super virulent Omicron—is what is known as a Frankenstein or ‘recombinant’ strain.

This means it emerged when a person was infected with two Covid strains at once which then became a new hybrid variant. 

Professor Lawrence Young, a virologist at Warwick University, told MailOnline both two strains of Stratus—the original XFG and spin off called XFG.3— are ‘rapidly spreading’. 

‘The increased competitiveness of XFG and XFG.3 is likely due to new spike mutations which make these variants more able to evade the immune response,’ he said. 

‘Given that immunity to Covid is waning in the population due to a decline in uptake of the spring booster jab and the reduction of Covid infections in recent months, more people will be susceptible to infection with XFG and XFG.3.

‘This could lead to a new wave of infection but it’s difficult to predict the extent of this wave.’

However, he added that there is currently no evidence Stratus causes more severe illness and getting a Covid vaccine was ‘very likely’ to offer protection from severe illness and hospitalisation.

Stratus’ rise comes just a week after the World Health Organisation (WHO) declared the strain a ‘variant under monitoring’.

This designation means health authorities across the globe have been asked to help track the variant due its rising spread in different countries and the potential public health implications.

Whilst assessing the overall risk of Stratus as ‘low’ the WHO said evidence pointed to the variant having significant growth advantage compared to other strains with it now accounting for 22 per cent of cases recorded globally. 

Nimbus—another new Covid variant also tipped to drive a wave of new infections—has also soared in recent weeks.

That strain has gone from just 2 per cent of cases in April to 17 per cent in June, according to UKHSA data.

However, overall Covid cases are on the decline compared to recent weeks.

Just 5.4 per cent of Covid tests analysed by UKHSA in the week ending June 29 were positive for the virus.

This is a slight fall from the 7 per cent of tests that came back positive the week prior, which as the highest positivity rate recorded so far this year.

Neither Nimbus nor Stratus are thought to cause new symptoms compared to previous strains. 

However, medics have warned that anyone with a ‘razor blade’ throat could have Nimbus.

Dr Michael Gregory, regional medical Director for NHS England in the North West recently said: ‘The variant looks to be spreading rapidly within communities, with top symptoms being a “razor blade” sore throat and swollen neck glands.’ 

But any Covid infection with the virus can still be deadly, especially for more vulnerable groups like the elderly or those with compromised immune systems.