The new Covid variant labelled ‘Stealth Omicron’ could be 1.5 times more infectious than the original strain, latest studies have revealed.
Brett Gibbons www.devonlive.com
The new strain BA.2 has been deemed a variant under investigation (VUI) by the UK Health Security Agency (UKHSA) because of its similar properties to original cases, the Express reports.
The BA.2 has been nicknamed “Stealth Omicron” because of the challenge for scientists to track, unlike the original strain that stood out on PCR tests without the need for extra genome sequencing.
Experts now fear it may lengthen the current wave, with a growth in Omicron infections among children – with boffins from Imperial College London warning this could lead to another surge in adults.
Results from the government-backed REACT-1 study, based on more than 100,000 random tests across England, show the infection rate in primary school-age children was 7.8 percent — and rising — from January 5 to 20.
In adults, by contrast, infection rates were significantly lower — and falling — with over 75s, at 2.4 percent, least likely to have Covid.
Professor Paul Elliott, director of the REACT programme from Imperial’s School of Public Health, said: “There is good news in our data in that infections had been rapidly dropping during January, but they are still extremely high and may have recently stalled at a very high prevalence.
“Of particular concern is that there is rapidly increasing prevalence among children now they are mixing more following the start of the school term and, compared with December, prevalence in older people aged 65 and over has increased 7- to 12-fold, which may lead to increased hospitalisations.
“It’s therefore vital that we continue to monitor the situation closely to understand the impact of the Omicron variant, which now makes up almost all infections in the country.”
The new sub-lineage of the Omicron strain is “increasing in many countries”, as confirmed by the World Health Organisation. It said BA.2, “differs from BA.1 in some of the mutations, including in the spike protein”.
Early data suggests that BA.2 may be both more transmissible and better able to evade vaccines than the more common BA.1 sub-lineage. While it has not yet caused as much concern as Delta and the original Omicron variant, officials are monitoring the outbreak.
Professor Oliver Johnson, director of the Institute for Statistical Science at Bristol University, said: “Probably one to keep an eye on rather than panic about at the moment, but still potentially annoying.”
He added on social media: “It may mean things being a slog in the ‘1,000 to 2,000 [hospital] admissions’ range for longer than we’d like, so we can’t start to make inroads into waiting lists as a result.”
Dr Meera Chand, Covid incident director at UKHSA, claimed: “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.”