New Delta Plus COVID-19 strain on rise in UK: Is variant more contagious? Should India be worried?

A new mutation of the Delta variant of COVID-19, which was being monitored and assessed in the UK, has now been classed as a Variant Under Investigation (VUI) amid concerns of its increased growth rate, with experts warning it is a reminder that the pandemic is not over.

AY.4.2, dubbed 'Delta Plus' and now named VUI-21OCT-01 by the UK Health Security Agency (UKHSA), has been under closer scrutiny in recent days after evidence indicated that it spread more quickly than the dominant Delta variant.

India’s COVID genomic surveillance project is also on high alert after the detection of the delta variant in the UK and the USA. The scientists have indicated that the new variant may be even more transmissible than the delta strain.

So far, the new variant has not been detected in India in over 68,000 samples from SARS CoV 2 infected patients that have undergone whole genome sequencing under the INSACOG project, reported The New Indian Express.

When asked if the new variant is capable of triggering a new wave by India Today, Dr S Swaminathan, director, Infectious Diseases and Infection Control at Gleneagles Global Hospitals, said that coronavirus is moving towards an endemic stage, which will continue to have waves of infections, but will not stop life.

"Mutations of a virus is inevitable. Flu does that every year, why will COVID be any different? Please understand that just because we have found a mutant doesn't mean it is a problem. The best we can do is vaccinate, which we have done  aggressively. So, even if we do have a new wave, it will be so mild that it will not tax the system as it did this year," said Swaminathan.

While evidence is still emerging, so far it does not appear the new VUI causes more severe disease or renders the vaccines currently deployed any less effective.

“However, we will raise surveillance and more samples will be tested from among the international passengers in the coming days—so that we don’t miss the possible infections caused due to AY 4. 2 and those infected are quickly identified,” said a senior official attached with the National Centre for Disease Control which is leading INSACOG.

"The Delta variant sub-lineage known as Delta AY.4.2 was designated a Variant Under Investigation by the UK Health Security Agency on 20 October 2021 and has been given the official name VUI-21OCT-01," the UKHSA said.

The designation was made on the basis that this sub-lineage has become increasingly common in the UK in recent months, and there is some early evidence that it may have an increased growth rate in the UK compared to Delta.

More evidence is needed to know whether this is due to changes in the virus' behaviour or to epidemiological conditions, it said.

"The genome of VUI-21OCT-01 does not have many mutations compared to Delta. However, a small change may be enough to cause a difference in the virus properties in some circumstances. UKHSA is monitoring this closely, the health agency in charge of assessing COVID variants in UK noted.

Viruses mutate often and at random, and it is not unexpected that new variants will continue to arise as the pandemic goes on, particularly while the case rate remains high, said Dr Jenny Harries, UKHSA chief executive, as per PTI.

Data suggests AY.4.2 could be 10 percent more transmissible than the most common UK Delta variant, AY.4, Francois Balloux, PhD, director at the University College London Genetics Institute, posted to social media, reports Healthline.

The Centers for Disease Control and Prevention (CDC) Trusted Source says the Delta variant is highly contagious and more resistant to treatment than the original variant. A 10 percent increase could make the new variant the most infectious yet.

However, experts say that more infectious doesn’t necessarily mean greater cause for concern. “Well, transmissible does not mean more dangerous,” said Dr. Len Horovitz, internist and pulmonary specialist at Lenox Hill Hospital in New York. “Doesn’t mean more virulent.”

He explained what it does mean is that the virus’s incubation period is shorter, so it can be transmitted faster and spread more easily than one that requires longer incubation.

“Transmissibility does not equate with virulence,” he emphasized. “So we don’t know if these cases will be more serious.”

Though the emergence of a COVID subtype isn’t the same as an entirely new variant evolving, keeping track of delta’s progression could allow the medical community to better understand the mutation, Dr. Sylvain Aldighieri, COVID-19 incident manager at the World Health Organisation’s regional branch for the Americas, said at a briefing Oct. 6, reports CNBC.

According to a report by CTV News, Canada has also seen emergence of a small number of cases of the new strain, said according to Dr Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan.

"In many places, we still don't have the surveillance capacity to find these variants if they emerge," she said. "They also might not be emerging. We haven't really seen anything that indicates that this is becoming prevalent in Canada."

Dr Rasmussen also believes it's likely the vaccines currently deployed in Canada will be effective against the subvariant.

"The vaccines that we currently have are quite effective against original recipe Delta," she said. "Of course, we should wait and see, we should take a look at it, but there's really nothing that stands out to me as a concern as far as vaccine effectiveness against this particular sub-lineage."

With inputs from PTI