Scientists say UK strain unlikely to affect efficacy of COVID-19 vaccines, warn against more mutations

faster spreading coronavirus strain first detected in UK is unlikely to make vaccines less effective as of w but preventives may need to be appropriately altered if more mutations occur over time, say scientists.

More than 40 countries, including India, have banned travel to and from UK, a move several scientists said was necessary in view of rapid spread of new viral strain, VUI-202012/0, that was detected on September 21.

According to Jeremy Farrar, director of London-based research charity Wellcome Trust UK, re is indication at moment that new strain would evade treatments and vaccines.

  However, mutation is a reminder of power of virus to adapt, and that cant be ruled out in future. Acting urgently to reduce transmission is critical, Farrar said in a statement.

    European Centre for Disease Prevention and Control (ECDC) anunced on Sunday that rapid increase of a SARS-CoV-2 variant with multiple spike protein mutations have been observed in UK.

  Preliminary modelling results communicated by UK on December 19 suggest that variant is significantly more transmissible than previously circulating variants, with an estimated increase in reproductive number (R) by 0.4 or greater with an estimated increased transmissibility of up to 70 per cent, EDC said in a statement.

  R number detes expected cases directly generated by one case in a population while transmissibility is ability of a virus to be passed on from one person to ar.

  ECDC, however, said re is indication of increased infection severity observed related to variant. assessment is challenged by fact that majority of cases were reported in people under 60 years who are less likely to develop severe symptoms, it said.

  new strain of virus is kwn to have 13 mutations in spike protein of which N501Y mutation is responsible for it spreading 70 per cent faster than earlier versions of virus, said Deepak Sehgal, professor and head of department of Life Sciences, Shiv Nadar University.

  N501Y is mutation. 501st position in spike protein's ami acid chain has altered from asparagine, deted by letter N, to tyrosine, represented by letter Y, refore N501Y, scientists explained.

Spike protein is a crown protein on virus which comes in contact with human cells to enter and infect.

  Sehgal ted that new variant has mutations to spike protein that three leading vaccines are targeting. three leading vaccines are Moderna, Pfizer and Oxford-AstraZeneca.

“However, vaccines produce antibodies against many regions in spike protein, so it’s unlikely that a single change would make vaccine less effective,” Sehgal told PTI.

  Over time, as more mutations occur, vaccine may need to be altered.

This happens with seasonal flu, which mutates every year, and vaccine is adjusted accordingly, Sehgal explained.

SARS-CoV-2 virus, however, doesn’t mutate as quickly as flu virus, he added.

  Virologist Upasana Ray agreed with Sehgal, ting that re is t eugh evidence to suggest that se mutations may affect efficacy of current vaccine candidates.

   “It is important to remember that we don’t kw wher this variant is a ‘serotype’ (variant)," Ray, a senior scientist at CSIR-IGIB Kolkata, told PTI.   

She explained that it is still unkwn if new strain interacts with host immune system differently compared to or existing variants.

  As such, re is evidence to date that this variant alters disease severity, eir in terms of mortality or seriousness of cases of COVID-19 for those infected.

  She said structural proteins of a virus are responsible for attachment of virus receptor and co-receptor in cells, ultimately leading to entry of virus inside host cells.   

Thus changes in structural protein might influence strength of virus-receptor interactions and thus infectivity, she added.

  researchers said experimental data suggested mutation N501Y of coronavirus was seen to enhance infection in mice and led to increased infectivity and virulence.

  Mutation threat in spike virus may lead to faster entry of virus into human cells increasing infectivity. Only one change of ami acid from asparagine to tyrosine has made difference in strain enhancing its transmissibility, Sehgal added.

  One of most significant changes is an N501Y mutation in spike protein that virus uses to bind to human ACE2 receptor through which virus enters body.

  Changes in this part of spike protein may, in ory, result in virus becoming more infectious and spreading more easily between people, said Sehgal.

  researchers supported temporary travel bans to and from UK to stall spread of new viral strain.

  ECDC said re were indications of a more widespread occurrence of cases across UK, adding a few cases were detected in or countries as well.

  Italy reported that a citizen who had recently travelled to UK tested positive for new strain of virus.

  strain has also been found in Australia, South Africa, Brazil and Italy. It is absolutely essential to stop travel to spread this new strain in world, Sehgal said. 

“ countries where this virus strain has t been reported may be due to n-testing and hence t kwn. So to ascertain existence or spread of strain, all countries require thorough testing of circulating viral strains,” he added.

new strain was first detected in UK in September. In vember, around a quarter of cases in London were new variant. This reached nearly two-thirds of cases in mid-December.