Britain banned all arrivals from Portugal and every country in South America as fears grow over the Brazilian Covid variant.

The emergency decision was made after scientists suggested that the strain had the ability to re-infect previous Covid-19 sufferers and may not be stopped by current vaccines.

Health minister Matt Hancock announced on Thursday that the UK had delivered three million vaccine shots.

This figure could soon be turbocharged after a vaccine launch began in community pharmacies.

Portuguese flight ban a UK Covid first

Prime Minister Boris Johnson raised the alarm over the new strain on Wednesday, saying the government was concerned about the new Brazilian variant.

The ban on all flights from Portugal from 4am on Friday is the first time Britain has stopped travel from a European country during the pandemic and a sign of how seriously the government is treating the E484K variant found in the Brazilian and South African strains.

Scientists believe the mutant virus may evade antibodies made against the older variant, allowing re-infections that could make current vaccines less effective.

While there are few direct flights between South America and the UK, there are dozens to and from Portugal, a favoured holiday and retirement destination for the British.

But Portugal has strong former colonial ties with Brazil and numerous flights to the country, making it an unacceptably high risk for spreading Covid.

Transport secretary Grant Shapps said the decision had to be made urgently.

“The government has taken the urgent decision to ban travel to the UK in order to prevent the spread of a new strain of coronavirus into the UK,” his department said. “The decision to ban travel from these destinations follows the discovery of a new coronavirus variant first identified in Brazil, that may have spread to countries with strong travel links to Brazil.”

...we don’t know for sure” if the Pfizer, AstraZeneca and Moderna vaccines would work on the Brazilian and South African strains

Patrick Vallance, Chief Scientific Officer

The decision comes a few days after Britain took the UAE off its international travel corridor list after a surge of infections in the Gulf with passengers from the Emirates now required to quarantine for 10 days.

Scientists fear that the world could face a significant threat from E484K.

Patrick Vallance, the UK’s chief scientific adviser, said “we don’t know for sure” if the Pfizer, AstraZeneca and Moderna vaccines would work on the Brazilian and South African strains. “There’s a bit more of a risk that this might make a change to the way the immune system recognises it but we don’t know,” he told ITV. “Those experiments are under way.”

He did say, however, that it would be straightforward to adapt vaccines to the new strains.

Scientists are concerned that the virus possibly originated in Manaus, a city that suffered very high infections and deaths from the original strain but as a result was thought to have established herd immunity.

Research published last year stated that 76 per cent of people in Manaus had caught the coronavirus by October, which should have substantially restricted the virus’s spread. But Manaus experienced an unexpected surge of new cases last month and has now declared a state of emergency after hospitals reached 100 per cent capacity.

Brazil has suffered 206,000 deaths and more than eight million people have caught Covid, with a record 87,000 infections in a day on January 7.

The new restrictions will give returning travellers just 12 hours to find their way home, potentially leading to chaos at airports.

The Brazilian strain was first announced last Monday after Japanese health officials identified four air passengers arriving in Tokyo from Brazil’s Amazonas state as carriers. Subsequently the UK government has been studying the best ways to alleviate the threat.

Panama and Cape Verde will also be included in the British ban decided by ministers on the government’s Covid-O committee.

Mr Shapps said there is an exemption for British and Irish citizens with residence rights but that they must self-isolate for 10 days with their households.

The government has come under sustained attack for failing to enforce quarantine measures, and a similar failure with the Brazilian variant could be catastrophic if it can evade current vaccines and natural immunity built up through infection.

The government was also facing criticism on Thursday for delaying the enforcement of a requirement for travellers arriving in England to receive a negative Covid-19 test before departure.

Immunity can last up to five months

A Public Health England study unveiled on Thursday reported that infection confers immunity for at least five months – although this thesis has not been tested against the new strains. The study also found that even those with high levels of immunity could still pass on the virus.

"It is therefore crucial that everyone continues to follow the rules and stays at home, even if they have previously had Covid-19," PHE researchers said.

UK case rate starting to plateau in some regions

The UK reported a further 48,682 confirmed infections on Thursday but the release of the daily death toll was delayed.

Although not reflected in deaths after yesterday's record daily toll, the Covid case rate appears to be slowing.

"It looks like in London, in particular, and a couple of other regions in the South East and East of England, hospital admissions may even have plateaued, although it is hard to tell if they are coming down," Prof Neil Ferguson of Imperial College London told BBC Radio 4's Today programme.

"It has to be said this is not seen everywhere – both case numbers and hospital admissions are going up in many other areas but overall, at a national level, we are seeing the rate of growth slow."

The news will offer a scintilla of comfort to overburdened NHS staff, battling day and night to keep the pandemic at bay.

It comes as NHS England data showed that there were 4.46 million people waiting to start hospital treatment in November last year – the highest figure since records began.