The Brazil variant of coronavirus that has just been identified in the UK could spread faster than previous versions, a leading medical expert has said.
Dr Susan Hopkins, the chief medical adviser to NHS Test and Trace, also warned that the variant could have an impact on existing COVID-19 vaccines.
Six cases of the P1 variant first detected in the Brazilian city of Manaus have been found in the UK – three in England and three in Scotland.
Health officials are hunting one of the three in England, who remains unidentified after they left out their contact details on their COVID-19 test registration card.
Dr Hopkins, who is also strategic response director at Public Health England (PHE), told BBC Radio 4’s Today programme on Monday that the Brazilian variant shares traits with the South African one.
“This P1 variant that emerged in Manaus in Brazil is really quite similar to the B1351 from South Africa and they have a number of mutations that are suggested to increase transmissibility," Dr Hopkins said.
“Manaus in particular reported that a number of individuals were reinfected with this variant, and therefore that suggests that having had prior immunity from primary infection wasn’t enough to reduce infection and transmission.
“And that may also impact on the vaccine.”
Boris Johnson said on Monday: “If you look at what we have done in the case of the South African variant, a massive effort went in there.
“The same is going on now to contain any spread of the Brazilian variant.”
He said there was “no reason not to think that our vaccines are effective against these variants of concern at the present time”.
Watch: First cases of Manaus variant found in UK
Despite the detection of cases of the Brazil strain, Dr Hopkins hopes it will not become the dominant variant in the UK.
“I think the importance here is that, while we’re in national restrictions, while we have very transmissible variants that are circulating, then we hope that there isn’t any other variant that will be able to take over,” she said.
“However, as we start to release national restrictions with the schools going back on 8 March, that is where the risk starts to increase, and that’s why we really are clamping down on a number of measures to prevent the spread of these variants.”
She said people identified with the variant so far had all followed the rules – including quarantining and getting tested when symptoms emerged.
“We haven’t detected it in any individual who hasn’t had a history of travel or had a contact with travel yet, so that is good news," she added. "But we are prepared to search it out in the communities, if it is there.”
Two of the three English cases featuring the Brazil variant were confirmed in South Gloucestershire, but the third could be anywhere in the nation.
Anyone who took a test on 12 or 13 February and has not received a result, or has an uncompleted test registration card, is being asked to come forward immediately, as health officials try to track down the individual.
The Gloucestershire cluster was said to originate from one individual who travelled back from Brazil and arrived in London on 10 February – five days before the government’s quarantine hotel policy came into force.
PHE and NHS Test and Trace are contacting passengers on Swiss Air flight LX318 travelling from Sao Paulo, through Zurich, and landing in London Heathrow on that date.
Surge testing will be carried out in the Bradley Stoke, Patchway and Little Stoke areas of South Gloucestershire.
The remaining unlocated case is not believed to be linked to the others because the virus was found to have slight genetic differences.
Officials said the individual’s test was processed on 14 February, so believe it is likely they took it a day or two earlier.
Vaccines minister Nadhim Zahawi told Sky News on Monday: “In terms of its profile, this P1 variant is much closer to the South African variant, which we’ve been dealing with now for several weeks by surge testing, genome sequencing and isolation.
“This variant is a variant of concern, it is very similar in terms of its mutations to the South African variant. So it is concerning.”
Graham Medley, professor of infectious disease modelling at the London School of Hygiene and Tropical Medicine and a Sage member, said challenges such as the new Brazilian variant could mean the UK needing to “go backwards” in terms of relaxing restrictions.
He told BBC Radio 4’s Today programme: “It is a variant of concern but we are going to be faced with these in the next six months as we move towards relaxing measures – there are going to be challenges on the way – and there is always a risk that we might have to go backwards, and that’s what nobody wants to do, is to actually open up and then have to close down again.”
Watch: How England will leave lockdown