A year after the first coronavirus case was confirmed in Britain, there are now around 4,000 variants of the virus around the world, the UK Vaccine Minister announced this week.
Virus variants are not unusual, there have been many mutations in coronavirus since it emerged in 2019.
This is to be expected – SARS-CoV-2 is an RNA virus and these viruses mutate and change.
However, some of the mutations are causing more concern than others because of their ability to transmit more quickly or because they are likely to be more resistent to vaccines.
In Brazil, a variant called P1 is believed to be more transmissible and has led to a state of emergency being declared in Manaus in the Amazon.
In Wales, a variant linked to South Africa has been causing the most concern among officials.
The South African variant, also known as the B.1.351 variant, which is thought to be more contagious, has been identified in 13 cases across Wales – three of which have no links to international travel.
In a Welsh Government press briefing on February 3, Health Minister Vaughan Gething said: “Public Health Wales is carrying out a detailed and forensic investigation into each of these cases to discover when and how each person became infected with the South African variant strain and whether there is any evidence of wider community spread.
“We are working around the clock to discover how these three people became infected with the South African variant and we will do everything we can to keep people safe.”
Mr Gething said that the emergence of new strains meant it was more important than ever to follow the rules.
He said: The emergence of all these new strains – first the Kent strain, which has quickly become the dominant form of coronavirus in Wales, and now the South African and two Brazilian variants – mean it’s more important than ever that we all follow the rules, especially the basics.”
But what exactly do scientists know about the new variants? and how worried should we be?
A variant of the virus first discovered in Kent, South East England, was one of the initial causes of concern for scientists.
The UK variant, known as B117 was discovered during an investigation into why coronavirus cases in Kent continued to rise during the November lockdown.
Public Health England found a cluster of cases caused by a variant with a high number of mutations. When they looked back at the genetic sequences of viruses collected in the months before, they found that it first emerged in Kent on 20 September.
Prime Minister Boris Johnson told a press conference on Saturday, December 19, that the data was still only from early studies and may be reviewed but that the early indications were: “It may be up to 70% more transmissible than the old variant.”
By January, Sir Patrick Vallance, the chief scientific adviser for the UK government suggested the Kent variant might increase the case fatality rate by 30 per cent.
In Wales, it was the discovery of the Kent variant that prompted the Welsh Government to bring forward tier four restrictions on December 19 2020.
The variant is now the dominant strain of coronavirus circulating in Wales.
While there are concerns about the speed in which the variant jumps between humans, research into efficiency of vaccines against the variant have been positive.
Moderna announced on Jan 25 that its Covid-19 vaccine produced virus-neutralising antibodies in laboratory tests against the new coronavirus variants found in the UK.
Preliminary research under review by the Lancet shows that among the small number of people included in the study, vaccine efficacy of the AstraZeneca jab fell from an average of 84% against older variants to 75% against the Kent variant.
South African variant
In Wales, the South African variant is one scientists are particularly concerned about.
TThe Kent variant and the South African variant share a similar set of mutations in the spike protein of the virus – but they are not identical.
The biggest concern about the South African variant, according to Health Minister Vaughan Gething, is that it reduces the effectiveness of the vaccines.
The South African variant, also known as the B.1.351 variant, which is thought to be more contagious, as been identified in 13 cases across Wales – three of which have no links to international travel.
Work is still being carried out to establish how effective vaccines are against the variant. However early studies suggest that although they may be less effective, they still help the immune system fight the virus and reduce the chance of serious illness.
According to the New Scientist magazine : “It isn’t yet clear if B.1.351 is more transmissible, but it is certain that it can partly evade the immunity we develop from natural infection by other coronavirus variants and from vaccines. The big worry is that it could evolve further and completely evade immunity, undermining vaccination efforts.
The magazine reported that the South African variant in the UK had developed a mutation known as E484k.
It said: “Ravindra Gupta at the University of Cambridge and his colleagues have already confirmed that this new B.1.1.7 plus E484K variant is better at evading immune protection. In other words, this is a faster-spreading virus that is also better at evading immunity.”
However, worryingly, Oxford-AstraZeneca’s vaccine offers “minimal protection” against mild disease from the South Africa variant, scientists say early trials suggest.
A study outlining early trials, first reported by the Financial Times , suggests the vaccine offered “minimal protection” against mild and moderate disease caused by the variant, the University of Oxford said.
A new study, not yet peer reviewed, involved about 2,000 people who were on average 31 years old.
But Prof Sarah Gilbert, Oxford lead vaccine developer, said vaccines should still protect against severe disease. She said developers were likely to have a modified Oxford jab by the autumn to combat the South Africa variant.
Similarly to the Kent and South African variants, the Brazil mutation is also thought to be more contagious or easy to catch than earlier versions.
There are actually two Brazilian variants. One – known as P.1 – was detected circulating in an city called Manaus in northern Brazil by scientists in December. This is the one the government is most concerned about.
Scientists are particularly concerned about the situation in Brazil because this P1 variant has emerged in Manaus – where an estimated 75% of the population had already had coronavirus and should therefore have had protection through herd immunity.
Research published last year suggested that 76 per cent of people in Manaus had contracted coronavirus by October – a level so high it should have severely limited onward spread of the virus.
However, the city saw an unexpected surge of new cases last month and has now declared a state of emergency, with hospitals reaching 100 per cent capacity.
Professor Sharon Peacock, the director of the Covid-19 Genomics UK Consortium, said the Brazilian variant was worrying because it shared mutation with the UK variant, which is believed to have increased transmissibility between 50 and 77 per cent.
It also had other mutations which stopped antibodies from working.
A second Brazil variant – known as P.2. – has been spotted 11 times in Britain and carries a mutation which can bypass antibodies.
It is currently spreading around Rio de Janeiro and has been linked to two reinfection cases in Brazil.
On January 14, UK Transport Secretary Grant Shapps announced a ban on arrivals from South America: Brazil, Argentina, Bolivia, Cape Verde, Chile, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Suriname, Uruguay, and Venezuela.
“Travel from Portugal to the UK will also be suspended given its strong travel links with Brazil – acting as another way to reduce the risk of importing infections. However, there is an exemption for hauliers travelling from Portugal (only), to allow transport of essential goods,” he tweeted.
“The fact the virus has the N501 means we know that it’s likely to be more transmissible, so that already rings alarm bells, and if it’s then carrying other mutations which could have other properties then we clearly need to take it seriously. But we have the tools to detect this and the public health capabilities to prevent spread,” said Prof Peacock.
The P.1 variant has not been picked up in testing in Britain but the second P.2 variant has been here ‘for some time’ according to scientists, and has been picked up in 11 genomes.
In Wales, Chief Scientific Adviser Rob Orford said the situation was being monitored “very carefully in Wales”.
“We’re very fortunate in Wales to have a very good system in place where we sequence many of the positive Covid test that we that we have back,” he told the BBC.
There is no definitive word on this at present but experts have suggested that vaccines will offer protection against other variants that have been detected. It may be, however, that the immune response they produce is not as strong.
-- to www.walesonline.co.uk