Kent Covid variant sweeping the world may be more infectious than original strain because it leaves patients sicker for longer, scientists say
- Data from 65 players and staff from the US National Basketball Association
- People normally only get a test when they have symptoms but the NBA test daily
- Analysis suggests Kent strain is up to 70% more transmissible than the previous
Britain’s Kent Covid variant could be more infectious because people stay sicker for longer, scientists now believe.
More than 50 countries have already spotted the mutant B.1.1.7 strain, which evolved to become up to 70 per cent transmissible than the original virus.
But researchers from Harvard University believe it may actually be because it leaves patients infectious for longer.
They found patients infected with the new variant were ill for 13 days, compared with eight days for the original SARS-CoV-2 strain.
The study — not yet published in a medical journal — used data from 65 players and staff in the US National Basketball Association who had contracted Covid.
People normally only get a test when they have symptoms but the NBA test daily and continue to do so after a positive swab, to monitor the full extent of the virus.
The Kent variant was first detected in in September 2020 and its rapid spread across the country spooked No10 into tougher action in December.
As well as being more infectious, studies also suggest the variant is slightly deadlier. But all the evidence suggests current vaccines work against it.
Eric Topol, director of the Scripps Research Translational Institute in California, told The Times they first thought the extra infectiousness of the UK variant was because of a ‘higher viral load’.
It’s thought that the amount of virus particles someone has inside them — known as the viral load — determines how sick they will be. Studies also suggest a high viral load makes people more likely to infect others.
However, the new data suggests it is related to ‘longer duration of infections’.
The study of the 65 players and staff found that the seven who were ill with the new variant were ill for 13 days.
In comparison, the 58 who were infected with the old strain were sick for eight days.
Those who tested positive with the old variant took two days from when Covid was detected to reach peak viral load and another six days until it was undetectable.
Meanwhile, those infected with the Kent variant took five days from when the virus was detected to reach peak viral load and then eight days until it could no longer be detected.
Dr Jenny Rohn, a biologist at University College London, told how the findings have ‘serious implications’ given the current quarantine period of 10 days.
It suggests Britons infected with the Kent variant – which is the most dominant strain in the UK – may need to quarantine for longer, if the findings are proven true in further studies.
Professor Sharon Peacock, head of the Covid-19 Genomics UK (Cog-UK) Consortium said the Kent variant ‘is going to sweep the world, in all probability’.
There are fears the variant has started to mutate further to become more like the one that evolved in South Africa, which is better able to resist immunity developed by past infection or from the current vaccines.
It comes after a hybrid version of coronavirus surfaced in California after the British Kent variant and a strain found in the US merged together inside an infected person.
The variant, not yet named, has only been spotted once but scientists fear there are likely to be more cases.
Experts are worried because it carries mutations which appear to make it able to spread faster and also to slip past some of the immunity made from past infections or vaccines.
It was formed from the Kent Covid variant and a Californian variant called B.1.429.
Scientists in the US claim they merged in a ‘recombination event’, the New Scientist reports. This happens when two different versions of the virus infect the same cell and then swap genes while they are reproducing, giving rise to a new variant.
Researchers have warned in the past that these events are possible but said they are ‘unlikely’ because they require very specific conditions and the coincidence of mostly uncontrollable events. They are more likely to happen during huge outbreaks.
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