There are signs that Victoria could be moving past the peak of its current COVID-19 wave as the nation nears the end of its deadliest month since the pandemic began.
Victoria has reported more than 650 COVID-19-related deaths in July, surpassing the 505 deaths reported to authorities in June.
The number of deaths reported nationally in July has also surpassed the total recorded in January, when Omicron first stuck.
Not all COVID-19 deaths publicly reported in July occurred in the same month, but the figures give an indication of mortality trends.
"It's a huge challenge," Chief Health Officer Brett Sutton told the ABC.
"And it's an enormous matter of concern to me. But it's a global challenge at the moment."
Professor Sutton attributed the high death rate to the spread of the BA.4.5 and BA.5 Omicron sub-variants, which have taken hold across much of the country.
Deakin University's chair of epidemiology, Catherine Bennett, said Victoria was going through a "deepwater wave" of infections.
"While deaths are rare and we're not seeing a lot of people in ICU, thankfully, who have an infection, we still have such high infection rates [that] this is translating to deaths, particularly in the old and vulnerable," Professor Bennett said.
Recent Victorian mortality data underscored the protection offered by COVID-19 vaccines, with one third of deaths in the first half of 2022 occurring in unvaccinated people, despite them only making up less than 5 per cent of the population.
The majority of the state's deaths since the pandemic began have been in those aged 80 years and older.
However, Professor Sutton said, the state was "in our plateau phase now", suggesting the worst of the 2022 winter wave may be nearing an end.
"We may well have peaked in terms of case numbers, or we're just about to peak. Hospitalisations will follow," he said.
"That probably means we're just about to go into that plateau now. And they should be dropping in the next week or two.
"Deaths, unfortunately, are going to remain high and even rise over the next couple of weeks because of that lag from cases [being registered]."
National peak appears to be approaching
Professor Bennett said the experience of South Africa — which has been living with the BA.5 sub-variant for a longer period of time — suggested the cases could start to come down.
"So, hopefully, we are approaching the peak in those states and territories that saw this take off sooner," she said.
"Others ,like Western Australia, it probably happened a bit later.
"But even some of those areas, Tasmania as well, might be starting to slow up the curve of those infections reported in the hospital system."
Monash University's James Trauer — who heads up the institution's epidemiological modelling unit — said multiple indicators, such as case numbers and hospitalisations, suggested the wave may be cresting across the country.
He said that case numbers had been dropping in smaller states, such as the Australian Capital Territory, Tasmania and South Australia, whereas Victoria and New South Wales were "a little bit behind".
"Particularly in some of the smaller jurisdictions, the case numbers appear to be coming down and hospitalisations will lag that, but they also appear to be plateauing," he said.
He said factors such as test positivity rates, the decline in flu cases, the end of winter nearing and cases dropping in overseas countries pointed to the wave starting to turn around.
Reinfection likely key driver of BA.5 wave
Victoria's Chief Health Officer said new sub-variants appeared to be able to "get around our innate immunity, either from vaccination or previous infection".
"So it's allowing for a lot of transmission to occur," Professor Sutton said.
Recent serology testing suggested around half of Australians had been infected with COVID-19, which Deakin University's Professor Bennett said indicated rising general immunity in the population.
"And that should help us see through the other side of this BA.5 wave, even though BA.5 [has the ability to get around immunity] and we're dealing with all the challenges of that not being as well covered by our prior immunity," she said.
Reliable figures about the frequency of COVID-19 reinfections are hard to come by, but data from New South Wales reported this week showed that more than 20,000 people in the state who had the virus in January had since been reinfected.
Dr Trauer said it was hard to accurately gauge reinfection rates because many COVID-19 infections went unreported.
"I think reinfection is actually playing an even bigger role than that," he said.
Infectious diseases experts have repeatedly emphasised the importance of getting boosted when eligible, ventilating indoor spaces, wearing masks indoors and proactively investigating eligibility for antiviral medications as key to coping with the latest waves of infection.
Dr Trauer said death rates were still too high and more should be done to help prevent vulnerable people from dying, such as ensuring elderly people had received all available vaccine doses and administering antivirals to eligible people.
"If they're a high-risk category, they're essentially eligible for those treatments and it's going to potentially save their lives," he said.
Victoria's new pandemic legislation, passed in 2021, stripped the Chief Health Officer role of the power to make health orders and gave it to the Health Minister.
Earlier this month, the state's Health Minister, Mary-Anne Thomas, confirmed she had dismissed recommendations from the acting CHO to mandate mask-wearing in retail and early education settings.
Professor Sutton refused to be drawn on whether he was concerned about the rejection of that advice, but said he recognised the need for the minister to take on a variety of concerns.
"We've had a chequered history in Victoria. There has been frankly histrionic commentary in Victoria on masks that isn't science-based, that isn't evidence, so it isn't an easy decision to come to a mandate," he said.
Circulation of 'nastiest variant' around offers some hope
Professor Bennett said the fact that no new variants of concern had recently emerged meant there should be a relatively complication-free few months ahead.
"We're heading into spring. We end up with longer days, better weather, people being able to distance more naturally as part of their social networking," she said.
Ever since Omicron took hold, the number of Victorians in hospital with the virus has remained high, only dipping under 200 briefly in March this year.
"With summer on the way and, hopefully, no more variants that are really pushing that infection risk, we might get to a point where we not only turn this wave around but get our numbers down to something we haven't seen since January," she said.
Dr Trauer agreed the lack of new variants was cause to believe things would improve in the coming weeks and months.
"We've got the current, nastiest variant that's around and we're coming out of a wave with that, so that will be heading in the right direction at the same time as we're heading into spring," he said.
"Hopefully that will push us in the right direction."
