There’s a new COVID-19 variant spreading in the community in Australia and it’s causing ‘significant concern’.

The Delta variant, which has become infamous for causing devastation in India and the UK, has been detected in Victoria’s outbreak.

On Friday morning genomic sequencing revealed that seven cases in Melbourne were infected with the strain.

It is different from the Kappa variant which caused the outbreak when an infected man left hotel quarantine in South Australia last month.

Victoria’s Chief Health Officer Brett Sutton told reporters on Friday the strain has not been linked to any of the other cases in the current outbreak, which means it is not related in terms of transmission.

“It has not been linked to any sequence cases across Australia, from hotel quarantine or anywhere else,” he said.

While the Delta variant has been found previously in Australian hotel quarantine, this is the first time it has emerged in community cases.

Just under half-a-million people have been tested since Monday of last week.

The difference between Delta and Kappa strains

The main strain associated with the current outbreak in Victoria has been the Kappa strain.

Kappa, which is also known as B.1.617.1, and Delta, called B.1.617.2, are both substrains of what’s commonly been referred to as the Indian variant — B.1.617.

The World Health Organisation made a decision this week to change the names of the strains to Greek letters, rather than the places where they were first detected.

In April, Delta was listed as a “variant of interest” by the World Health Organisation before being classified as a “variant of concern” in May.

“We continue to observe significantly increased transmissibility and a growing number of countries reporting outbreaks associated with this variant,” the WHO said in a report this week.

“Further studies into the impact of this variant remain a high priority for WHO.”

How concerned should we be?

All viruses mutate when they spread, but both the Kappa and Delta strains have a spike protein which has been associated with a higher transmissibility rate.

On Friday, Public Health England (PHE) warned residents of the United Kingdom that Delta may lead to an increased risk of hospitalisation and is now believed to be the dominant strain in the UK.

The Delta variant spread rapidly across India to reach 62 more countries, which is still a far cry from the Alpha (formerly known as the UK strain) which has so far hit 160 countries.

But authorities fear it may have a very high transmissibility rate, and there have been initial reports of greater illness in children.

“We’ve got concerns for that reason,” Professor Sutton said.

Will our vaccines still be effective? 

Although it can’t be ruled out that the vaccines may be less effective on the new strain, so far it’s good news.

A study by PHE of 44,549 vaccinated health workers found that when the strain became “highly prevalent” across the UK there was no increase in positive cases.

“In terms of vaccine efficacy, that is to be seen,” Australia’s Chief Medical Officer Paul Kelly said on Friday.

“There has been some work in the UK which suggests there may be a lower efficacy of AstraZeneca but it is not zero. That is preliminary laboratory work.

“We have to wait for the real-world experience which only comes when we have large outbreaks and I’m sure we will not be having those in Australia.”

-with AAP