A new Delta subvariant COVID-19 strain has been designated a “Variant Under Investigation” by the U.K., as new evidence suggests it may be 15% more transmissible compared to the Delta variant.

Is this sub-variant more transmissible than Delta?

According to the U.K. Health Security Agency (UKHSA), the strain which has two mutations that strengthen its transmissibility, does not appear to result in more severe disease or render vaccines less effective.

However, scientists believe the sub-variant is 10 to 15% more transmissible than the original Delta variant which has already dominated Covid cases around the world.

That would mean Delta Plus might be the most infectious variant to date.

why is the sub-variant still concerning?

The variant itself is not necessarily that worrying at the moment, but it does demonstrate that Covid itself is continuing to evolve.

Dr Barrett explained on Twitter: “What is perhaps more worrying is that it suggests the virus still has evolutionary paths to higher transmissibility open to it, and there are millions of Delta cases around the world without much sequencing coverage.”

This means there is still space for Covid to continue adapting for further human transmission.

How Far Has The Virus Spread?

The subvariant, which had previously been dubbed “Delta Plus” or “AY.4.2,” was first detected in England back in July. Data from the UKHSA shows an estimated 6 per cent of recent COVID-19 cases in the U.K., where case numbers have been surging, are of this Delta subvariant.

So far, the strain has been detected in the UK, the US and Canada.

A small number of cases of the new strain was identified in Canada, but it’s unclear if it’s more contagious than the Delta variant, according to Dr Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan.

Dr Rasmussen said the U.K.’s robust genomic surveillance, which sequences about 10 per cent of the positive COVID-19 cases they have, maybe a reason why they have detected more cases.

“In many places, we still don’t have the surveillance capacity to find these variants if they emerge,” she told CTV News Channel on Wednesday. “They also might not be emerging. We haven’t 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 nothing that stands out to me as a concern as far as vaccine effectiveness against this particular sublineage.”

There is currently no detection of the new strain’s presence in Africa as at the time of this report.