The UK issued stricter restrictions over the holiday season with officials stating that a new, more infectious strain of coronavirus was spreading rapidly in southeast England.
Prime Minister Boris Johnson said the new strain was up to 70% more transmissible than other variants, with it already accounting for over 62% of COVID-19 infections in London.
So what do we know about this new strain that is prompting UK officials to take more drastic steps to limit the spread of COVID-19?
When did officials first report about the new strain of coronavirus?
UK health minister Matt Hancock first announced that there was a new variant of coronavirus (a mutated version of the virus) in London and southeast England on December 14 in the House of Commons.
“Initial analysis suggests that this variant is growing faster than the existing variants,” Hancock warned, stating that it could be responsible for rapidly rising cases in the southeast of England, something officials would confirm later in the week.
Hancock said that more than 1,000 cases had been identified in 60 different local authority areas.
Maria Van Kerkhove, WHO’s technical lead on COVID-19, said on Monday that “so far, we don’t have any evidence that this variant behaves differently” but British officials said on Saturday that it was more transmissible, a reflection in part of how fast scientists are learning about the virus.
“We are aware of this genetic variant reported in 1,000 individuals in England,” Dr Mike Ryan, the director of WHO’s emergencies programme. “This particular variant seems to have become more prevalent in the UK,” he added on Monday.
“This kind of evolution or mutations like this are actually quite common,” said Dr Ryan, who added that there were several questions about significant variants. He said that the UK officials were being very transparent and had already shared the variant’s genome sequence.
“This is a variant, the N501Y, that’s actually being monitored already by our virus evolution working group. It’s come up in the context of a mink variant identified elsewhere,” said Van Kerkhove on Monday.
That N501Y is just one of the changes in this UK variant, according to a study of the variant’s genome published on Saturday.
Hancock said that they do not think this strain of coronavirus would fail to respond to a vaccine.
What are the changes to this coronavirus strain?
The UK’s chief scientific advisor Sir Patrick Vallance said on Saturday that the new variant has 23 changes, “many of them associated with changes in the protein the virus makes.”
“This is an unusually large number of variants. It’s also got variants in areas of the virus that are known to be associated with how the virus binds to cells and enters cells,” Vallance said. “So there are some changes which cause concern in terms of how the virus looks.”
He said studies and analysis had showed that the strain was more transmissible, meaning that it was spreading more quickly.
This variant first appeared in September and by November it was responsible for 28% of the COVID-19 cases in London. By the week of December 9, more than 62% of London’s COVID-19 cases were from this new variant, officials said.
“So what this tells us is that this new variant not only moves fast, its increase in terms of its ability to transmit, but it is becoming the dominant variant. It is beating the others in terms of transmission,” Vallance said.
Officials said that due to its higher transmissibility, the variant would cause an increase to the country’s reproduction number – the R number – which is the average number of secondary infections from a single infected person.
That number is currently between 1.1 and 1.2 in England, meaning that “on average, every 10 people infected will infect between 11 and 12 other people”, the UK government states.
That number could increase by 0.4 due to the new variant, officials said on Saturday, meaning the epidemic would be spreading much faster. Any R number over one means that the epidemic is growing.
Does this new variant cause more severe disease?
UK officials say that they do not think that the new variant causes more severe disease or more deaths, but it does spread more quickly which could cause big problems for infection numbers.
“There is no current evidence to suggest the new strain causes a higher mortality rate or that it affects vaccines and treatments although urgent work is underway to confirm this,” said Professor Chris Whitty, England’s chief medical officer, in a statement released on Saturday.
Vallance added on Saturday that there was no evidence that this variant causes more hospitalisations but that for now it’s a question of transmission.
“This virus spreads more easily and therefore more measures are needed to keep it under control,” he added.