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COVID-19 cases are doubling every 11 days in England, study finds © Getty Images

COVID-19 cases are doubling every 11 days in England, study finds

Published: 17th June, 2021 at 11:00
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Infections have increased by 50 per cent from 3 May to 7 June, driven by unvaccinated age groups, but scientists say we can take comfort in the protection the vaccines are providing.

COVID-19 cases are “rising exponentially” across England, driven by younger and mostly unvaccinated age groups, according to scientists tracking the epidemic.


A study commissioned by the Government found that infections have increased 50 per cent between 3 May and 7 June, coinciding with the rise of the Delta coronavirus variant which was first detected in India and is now dominant in the UK.

Data from nearly 110,000 swab tests carried out across England between 20 May and 7 June suggests COVID-19 cases are doubling every 11 days, with the highest prevalence in the North West and 1 in 670 people infected.

The experts from Imperial College London said their findings show a “rapid switch” between the Alpha (Kent) variant, which first appeared in the UK in September 2020, and the Delta variant in the last few weeks, with the latter accounting for up to 90 per cent of all coronavirus cases. But they stressed that the country is in a much different position than autumn last year when an exponential growth triggered a second wave of coronavirus infections.

“Prevalence is increasing exponentially and it is being driven by younger ages," said Stephen Riley, professor of infectious disease dynamics at Imperial and one of the study authors. “And it appears to be doubling every 11 days.

“Clearly that is bad news… but the key thing to point out here is that we are in a very different part of the epidemic in the UK and it is very difficult to predict the duration of the exponential phase.”

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The scientists said their findings from the REACT study suggest that imminent expansion of the coronavirus vaccine programme to those aged 18 and above “should help substantially to reduce the overall growth of the epidemic”.

“I think we can take quite a lot of comfort from the fact that when we look in the details, it does appear that there is very, very good protection in the older ages, where there is virtually everyone double vaccinated," said study author Prof Paul Elliott, director of the REACT programme and chair in epidemiology and public health medicine at Imperial.

“And in the younger group under the age of 65, where a much smaller proportion have been vaccinated or double vaccinated, most infections are occurring in the unvaccinated group.

“And the Government has clearly announced that they want to vaccinate all adults in the period between now and 19 July, I think that will make a very big difference and increase the total amount of population immunity.”

Graphic showing the number of COVID-19 vaccine doses in the UK as of 15 June © PA Graphics
© PA Graphics

The research, which has not yet been peer-reviewed, shows the bulk of infections is being driven by children aged between 5 and 12, as well as younger adults aged between 18 and 24. Infections in these age groups are around five times higher compared to those over 65, the researchers said.

Data showed that the “weakened link” between infection rates and hospital admissions was “well maintained” for those aged 65 and above, while “the trends converged below the age of 65 years”.

“We have observed this reconvergence in the pattern of hospitalisations and deaths versus infections, especially in an age group under 65," said Riley. “These patterns are consistent with two vaccine doses being highly effective.”

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Sara RigbyOnline staff writer, BBC Science Focus

Sara is the online staff writer at BBC Science Focus. She has an MPhys in mathematical physics and loves all things space, dinosaurs and dogs.


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