A leading virologist said one type of the strain had been found and had likely reached British shores “some time ago”.
Professor Wendy Barclay, who is advising the Government’s pandemic response, said on Friday: “There are two different types of Brazilian variants and one of them has been detected and one of them has not.”
She later clarified: “The new Brazilian variant of concern, that was picked up in travellers going to Japan, has NOT been detected in the UK. Other variants that may have originated from Brazil have been previously found.”
Shapps details South American travel ban
The scientist, who is leading a new project set up to study the effects of emerging Covid mutations explained: “In the databases, if you search the sequences, you will see that there is some some evidence for variants from around the world and, I believe, including the Brazilian one, which probably was introduced some time ago.
“That will be being traced very carefully.”
The Imperial College expert said both Brazilian variants – the one which was detected in Japan and the other which is more prevalent in Brazil currently – have mutations that suggest “they might impact the way that some people’s antibodies can see the virus”.
“It is really important that we carry out this work now, and carry it out carefully, and in several different laboratories, to really firm up those results because they have big implications,” she stressed.
The ban, which also covers the Central American state of Panama and Portugal – due to its strong travel links with Brazil – and the former Portuguese colony of Cape Verde, came into force at 4am on Friday.
Scientists analysing the Brazilian strain believe the mutations it shares with the new South African strain are associated with a rapid increase in cases in locations where there have already been large outbreaks of the disease.
British and Irish nationals and others with residence rights are exempted from the measures that were backed by the Scottish and Welsh governments, though they must self-isolate for 10 days along with their households on their return.
Travel to UK from all of South America and Portugal banned over Covid variant
Mr Shapps described the ban as a “precautionary” measure to ensure the vaccination programme rolling out across the UK was not disrupted by new variants of the virus.
Asked if the Brazilian strain was currently in the country, he told BBC Radio 4’s Today programme on Friday morning: “Not as far as we are aware, I think, at this stage.
“There haven’t been any flights that I can see from the last week from Brazil, for example.”
Meanwhile, Dr Mike Tildesley, an epidemiologist and scientific adviser to the Government, said the UK was late in imposing travel restrictions but that these should minimise the risk from the “more transmissible” variant.
“We always have this issue with travel bans of course, that we’re always a little bit behind the curve,” he told BBC Breakfast.
“My understanding is that there haven’t really been any flights coming from Brazil for about the past week, so hopefully the immediate travel ban should really minimise the risk.”
Dr Tildesley said although scientists “don’t believe there is anything to worry about” in terms of vaccine efficacy, the higher transmissibility could mean “people potentially might end up developing severe symptoms more rapidly which could cause more issues with our health service”.
Shadow home secretary Nick Thomas-Symonds said the ban – which includes an exemption for hauliers travelling from Portugal to allow the transport of essential goods – was a “necessary step” but accused ministers of incompetence and “lurching from one crisis and rushed announcement to another”.