Like the “UK variant” B.1.1.7 and “South African variant” B.1.351, the “Indian variant” B.1.617 is another variation of the virus that causes COVID-19.

It was first detected in India last October and has since spread to more than 40 other countries, including Australia.

Experts have identified three subtypes, or sublineages, of the “Indian” variant: B.1.617.1, B.1.617.2, and B.1.617.3.

Each sublineage is slightly different, but all have spike protein mutations that have been associated with increased transmissibility.

The spike protein is what coronaviruses use to gain entry into human cells.

Cases in Victoria’s latest cluster are infected with the first sublineage, B.1.617.1.

Is this variant more dangerous?

Experts believe B.1.617 could be more infectious than previous variants, based on how rapidly it is spreading in other countries.

“Preliminary reports from the UK, where B.1.617.2 is surging in some parts of the country, suggest it is 50 per cent more contagious than the UK variant B.1.1.7, which is already 50-100 per cent more contagious than the ‘regular’ strain,” infectious diseases expert Raina MacIntyre said.

We don’t know whether this variant is more deadly or causes worse disease than other versions of the virus.

But Professor MacIntyre said there was some data that indicated B.1.617 could cause different symptoms.

“Based on reports from India, this variant may have atypical clinical presentations, such as abdominal pain, nausea, vomiting, diarrhoea and hearing impairments, as well as an absence of fever,” she said.

“If this is the case, people should be on the alert for any of these symptoms as well as more typical COVID symptoms such as cough and fever.”

How concerned should we be about this variant?

While experts believe the “Indian” varian could be more infectious than other variants, there is some good news.

The same protocols that have been effective at controlling outbreaks previously — lockdowns, masks, and hygiene measures — will also be effective at bringing the latest virus under control.

How effective are vaccines against the ‘Indian’ variant?

More studies are needed, but early data from the United Kingdom is promising.

A recent study showed two doses of the Pfizer and AstraZeneca vaccines provided a similar level of protection against the B.1.617.2 variant, as they did against the B.1.1.7 UK variant.

“This study provides reassurance that two doses of either vaccine offer high levels of protection against symptomatic disease from the B.1.617.2 varian,” Public Health England’s head of immunisation Mary Ramsay said in a statement.

“We expect the vaccines to be even more effective at preventing hospitalisation and death, so it is vital to get both doses to gain maximum protection against all existing and emerging variants.”