‘Stealth’ Omicron: Scientists discover first case of new Covid variant in Liverpool City Region

The first case of the coronavirus strain branded ‘stealth Omicron’ has been found in the Liverpool City Region.

Cases of the Omicron sub-variant BA.2 have been in the UK for some time - the first example was found on 6 December, 2021.

But numbers are growing both here and abroad, and the UK Health Security Agency named it a ‘variant under investigation’ on January 21.

Early analysis suggests it has a faster growth rate than the Omicron strain currently dominant in the UK, BA.1, but there is not enough evidence to say whether it causes more severe illness.

The Wellcome Sanger Institute analysed 38,000 positive Covid-19 tests taken in the week to January 15 to determine which variant they were.

It found one in 100 samples were now Stealth Omicron across England.

Stealth Omicron in Liverpool City Region

Over 1000 test samples from across the six boroughs of the Liverpool City Region were tested by the institute and just one BA.2 variant was confirmed.

That case came in Knowsley, where 113 COVID tests were analysed, successfully identifying a COVID variant in all 113 of them. But only one of those was stealth Omicron, representing 0-9 % of those identified.

In the rest of the boroughs - Halton, Liverpool, Sefton, St Helens and Wirral - 972 test were analysed in total, successfully identifying a variant in 954 of them, but none were the BA.2 ‘stealth’ strain.

In nearby Warrington, stealth Omicron was also found. The institute analysed 218 tests from the area, successfully identifying a variant in all of them.  BA.2 was found in three tests, representing 1.4% of those identified.

Meanwhile, in the neighbouring city of Manchester the variant has also been identified. The institute analysed 462 tests from the area, successfully identifying a variant in 435 of them.  Stealth Omicron was found in four tests, representing 0.9% of those identified.

The variant was also found in a number of boroughs in the wider Greater Manchester area, with Oldham recording the highest rate at 2%.

What is Stealth Omicron?

It is not known where Stealth Omicron originated, with the first cases found in the Philippines and high numbers being reported in Denmark.

It got its nickname because it does not exhibit a tell-tale marker on its spike protein, revealed through a common type of PCR test, which the authorities had previously used to monitor the spread of Omicron.

But both PCR and lateral flow tests still identify Covid infection.

Dr Meera Chand, COVID-19 Incident Director at the UKHSA, said: “It is the nature of viruses to evolve and mutate, so it’s to be expected that we will continue to see new variants emerge as the pandemic goes on.

“Our continued genomic surveillance allows us to detect them and assess whether they are significant.

“So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1, but data is limited and UKHSA continues to investigate.”

Health secretary Sajid Javid said: “We are learning to live with this virus – and thanks to our world-leading surveillance system we can rapidly detect and carefully monitor any genetic changes to COVID-19.

“Our exceptional vaccine rollout means the number of people severely affected by COVID-19 is low, and the UK’s innovation and research has discovered life-saving treatments for those most at risk from COVID-19.”