Stealth Omicron sub-variant spreads 1.5 times faster than the original, study warns

A new study has warned about the new BA.2 sub-variant of Covid that spreads 1.5 times faster than its “sister” Omicron.

The initial calculations came from the leading infectious disease authority in Denmark, where the majority of the world’s BA.2 cases have been detected.

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“There are some indications that it is more contagious, especially to unvaccinated people, but it can also be contagious,” said Tyra Grove Krause, Technical Director of Statens Serum Institut (SSI). to those who have been vaccinated to a greater extent.”

Data from UKHSA last week showed the strain was more transmissible, but “no more severe” than the original Omicron variant that still prevails in the UK.

Denmark was one of the first countries to spread BA.2, meaning their data may give the clearest picture of the strain available.

It has reported around 20,000 cases of the strain compared with 2,500 for the UK.

But even if BA.2 could spread more rapidly, it is unclear how this would play out in a highly immune population – through vaccination or prior Omicron infection.

An initial SSI analysis showed no difference in the risk of hospitalization for BA.2 versus BA.1 – original strain omicron – Reuters reported.

“Overall, we have to say that the outbreak is still evolving and there is still a risk that the infection rate will increase further in the coming weeks,” Krause said.

“Therefore, there is also a risk that the number of admissions will increase. ”

“On the other hand, we expect hospitalization to be milder than before due to vaccination and the Omicron variant.”

The original Omicron strain, which BA.2 is very closely related to, is much lighter than the earlier variants.

People with Omicron infection are about 50% less likely to need to be hospitalized than those with Delta.

Scientists are not too worried about the emergence of BA.2 because so far, there is no signal that it will increase hospitalizations.

British epidemiologist Professor Tim Spector said he believes BA.2 is “no more severe” based on stable hospital admissions in Denmark.

Furthermore, UK data suggest that three doses of the vaccine are highly protective against BA.2, with enhanced injection efficacy against hospitalization up to 70%.

However, its higher transmission capacity may mean that the Omicron Covid wave will not be attenuated as soon as hoped.

The UK’s top medical leaders have said that the Omicron wave will likely include a spike in cases, before a very rapid decline.

And the forecasts were right – after a sharp rise in December, which peaked in early January, Covid infections in the UK quickly fell again.

But recently, after the discovery of BA.2, the slow down came to a halt. Cases are currently stabilizing at around 90,000 per day.

Eric Topol, director of the Scripps Research Translational Institute, said of BA.2: “Its increased transmission capacity will prolong the Omicron wave in many places.”

The recent stabilization of Covid rates is also due to the return of schools and the spread of infections in children to parents, experts say.

It comes after the UK’s Health Authority also said that BA.2 “has a higher growth rate than BA.1 in all parts of the UK”.

A report published on Friday warned: “While the growth rate may be overestimated in the initial analyzes of a new variant, the clear growth advantage is now well worth it.” tell.”

Analysis of cases to date shows that people with BA.2 are more likely to pass on stress to the people they live with, known as secondary attack rates.

The data reveals that although BA.2 has only been around for about a month, it has already surpassed Delta.

Wellcome Sanger Institute BA.2 claims are estimated to account for 2.8% of UK cases in the week to January 22, up from 0.8% a week earlier and compared with Delta’s 0.2%.

It comes after re-infection in the UK was counted for the first time during the pandemic.

Yesterday, 588,114 cases were added to the Government’s dashboard due to the inclusion of re-investigation, which were not previously included in the tally.

In addition, 173,328 previously unreported cases have been added and the daily number is 92,368.

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