‘Out of control’ new strain of coronavirus in UK
The UK has identified a fast-moving new variant of the coronavirus that is more than 70% more transmissible than existing strains. The new strain of coronavirus is now ‘out of control’, authorities have said. Here’s a summary of what leading experts have to say on the mutation reported in the country.
Experts said UK’s ‘more infectious’ Covid-19 strain spreads faster.
Dated : 21 Dec 2020 (IST)
Scientists, studying the widely reported mutation in the novel coronavirus, believe that there are still too many ‘unknowns’ as far as the effects of the mutation are concerned. The new lineage, code-named as B.1.1.7 has been widely tracked in the recent cases in the UK. Here’s a summary of what leading experts have to say on the mutation reported in the UK.
IS MUTATION IN A VIRUS ABNORMAL?
“This is quite normal for viruses — like influenza — where different viruses may infect the same person, leading to a hybrid virus emerging. This is just one of the ways that natural viral variation arises,” Dr Julian Tang, Clinical Virologist at the University of Leicester explained.
However, any change in behaviour of the virus depends on the nature and extent of mutation in any virus, including the one which causes Covid-19.
“Coronaviruses mutate all the time. So it is not unexpected that new variants of SARS-CoV-2 [Covid-19] are emerging, we see this all the time in other human and animal coronaviruses,” Prof Julian Hiscox, Chair in Infection and Global Health, University of Liverpool, said.
WHY IS B.1.1.7 SIGNIFICANT?
Since its detection in Wuhan, China, the SARS-CoV-2 has seen many changes. But, according to the preliminary genomic characterisation, the UK variant B.1.1.7 has an unusually large number of genetic changes, particularly in the spike protein which is often responsible for how the virus interacts with a human cell.
The reason which has set the alarms off in the UK and hence elsewhere are — first, this particular lineage accounts for an increasing proportion of cases in parts of UK and second, the number of linked cases as well as regions reporting B.1.1.7 infections have been growing.
This has forced many countries to put restrictions on UK travel. The Indian government is also seeking expert advice on the matter.
DOES IT AFFECT TEST RESULTS?
“One of the mutations in the new variant deletes six bases in the viral genome that encode amino acids 69 and 70 of the spike protein. By coincidence, this region is one of three genomic targets used by some PCR tests, and so, in those tests, that channel comes up negative on the new variant,” explains Dr Jeffrey Barrett, Director of the SARS-CoV-2 Genomics Initiative at the Wellcome Sanger Institute, UK.
However, if the PCR tests use the other two channels — not affected by the mutation — the tests should work fine.
“I’m not aware of any commercial tests that use just one target in this part of the viral genome. But if there are any, they should be carefully investigated,” Dr Barrett said.
Dr Robert Shorten, Chair, Microbiology Professional Committee, Association for Clinical Biochemistry and Laboratory Medicine said, “Labs know which genes their tests target and are vigilant about checking for test performance. PCR tests would generally detect more than one gene target so a mutation in the spike protein would not affect detecting other viral gene targets”.
IS THE NEW VARIANT MORE DANGEROUS?
The UK government officials suspect that the new variant could be more transmissible than the earlier versions of the virus. While scientists are still trying to understand the accurate explanation for this, some of them agree with the government’s reasoning.
Prof Peter Openshaw, former President of the British Society for Immunology, said, “It is right to take it seriously. Although there are only 23 mutations in the genetic code of 30,000 nucleotides, the variant does seem about 40-70 per cent more transmissible”.
However, he said that there is no evidence at the moment that the new variant causes disease which is any different from that caused by previous variants.
Dr James Gill, Honorary Clinical Lecturer, Warwick Medical School, said, “We are still waiting to learn further about this new strain and that has to be the key information here. It appears to be more contagious, but we do not know if it is more or less dangerous. Hence, stronger restrictions are sensible.”
WILL IT AFFECT VACCINATION AND TREATMENT?
Even though the mutation in the virus appears to be significant, experts have not found any reason to suggest that the new mutation would affect the vaccination as yet.
UK government’s advisory body New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) has released a paper in this regard as well.
“We are not seeing any increased virulence [clinical severity] or any gross changes in the S [spike protein] that will reduce vaccine effectiveness — so far,” said Dr Tang in response to the NERVTAG paper.
Dr Jeremy Farrar, Director of Wellcome Trust, agrees but issues a caution. He said, “At the moment, there is no indication that this new strain would evade treatments and vaccines. However, the mutation is a reminder of the power of the virus to adapt and that cannot be ruled out in the future.”