Everything we know about the risk and the reality of a second wave of COVID-19 in Australia.

In the past week, Victoria has seen a worrying increase in COVID-19 cases, sparking renewed concerns of a second wave that could disrupt Australia's 'return to normal'.

Most alarmingly, the majority of new cases in Victoria are infections that have been acquired within the community. For some, the source of infection is unknown. 

Already, this has led the government to extend their state of emergency for four more weeks until July 19. 

So what exactly does this all mean for Victoria? 

What is the latest on the outbreak in Victoria?

On Thursday, Victoria recorded 33 new coronavirus cases, the highest daily rise in two months and the ninth consecutive day of double-digit increases. 

The spike has seen the state's active cases triple since June 17.

It follows the news on Wednesday that a man in his 80s had died in Victoria from the virus — the first Australian death in a month from COVID-19. 

More than 1,000 military personnel have now been called in to help deal with the outbreak, which Premier Daniel Andrews has described as "a public health bushfire".

Premier Daniel Andrews also announced on Thursday they will significantly increase testing in an attempt to quash the outbreak. They are currently processing 18,000 tests a day, but will now actively aim to test 25,000 people a day. 

What is a 'second wave'?

As infectious disease experts James Wood and Nic Geard wrote for The Conversation, "When an outbreak is brought under control by social distancing and other measures, it’s possible only a small proportion of the population will have been infected and gained immunity.

"If a population has not achieved herd immunity, enough susceptible people may remain to fuel a second wave if controls are relaxed and infection is reintroduced."

Hence, it's more of a metaphorical term, rather than a medical term, to describe a sustained increase in new cases that occurs after the original surge has slowed down. 

If a second wave does occur, experts say it could be just as dangerous. 

For example, if we look at the 1918 Spanish flu, there were three waves of the illness during the pandemic. The first wave in the spring wasn’t that bad — it was the second wave in autumn that was the deadliest because it had mutated into a much deadlier version of its former self.

Listen to The Quicky, Mamamia's daily news podcast. On this episode, the team discuss the risk and reality of a COVID-19 second wave in Australia. Post continues below. 

Is Victoria experiencing a second wave now?

On Monday, Australia’s Chief Medical Officer Brendan Murphy said it was too early to determine if this outbreak would classify as a second wave. 

"There is no definite definition of that," he explained during a press conference. 

"If this outbreak escalated, and we had several hundred cases, that would be the sort of situation where I would be extremely concerned.

"But there is no official definition of a second wave, it’s a concept where the outbreak is such that you don’t think the public health measures can easily control it in the short term. At the moment, I have great confidence in the Victorian response, they are responding very effectively, and we need to watch things over the next few days to see how it happens."

Indeed, the state has since seen a return of strict restrictions, with a maximum of five people allowed inside the home, and gatherings outside the home restricted to 10 people.

What does it mean for Australia's plans of returning to normal?

On Thursday, Prime Minister Scott Morrison addressed this question, saying Australia is well-equipped to deal with infection spikes such as this.

"There are a few challenges in Melbourne at the moment but as we said, there will be outbreaks," he said.

"We can't go, stop, go, stop, go. We can't flick the light on and off."

The Prime Minister said the focus on the economic restart needed to remain as the nation adjusted to living alongside the disease.

"We are dealing with the coronavirus, the COVID-19, better than almost any country in the world and that's got to give us confidence to be able to move ahead," Morrison told reporters.

However, Australian National University's Professor Peter Collignon said, according to AAP, the next three months will be risky for Australians as the cold winter makes it harder to curb the spread of coronavirus.

If you are sick and believe you have symptoms of COVID-19, call your GP ahead of time to book an appointment. Or call the national Coronavirus Health Information Line for advice on 1800 020 080. If you are experiencing a medical emergency, call 000.

To keep up to date with the latest information, please visit the Department of Health website.

Feature Image: Getty.

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