Europe could soon enjoy a “long period of tranquillity” from the ravages of COVID, with the World Health Organisation (WHO) citing the end of winter, high vaccination rates and the less severe Omicron variant.

WHO’s Europe director Dr Hans Kluge said the continent’s vaccine protections could be seen as a “ceasefire” which would “bring us enduring peace”.

His comments come after a record 12 million new virus cases were reported across Europe last week without a significant spike in those needing critical care.

Dr Kluge said he was confident European nations, which have begun lifting COVID restrictions, would be in a “better position… even with a more virulent variant” than Omicron.

“I believe that it is possible to respond to new variants that will inevitably emerge without re-installing the kind of disruptive measures we needed before,” Dr Kluge added.

But as Europe transitions towards the end of winter, Australians have been warned to brace for a second wave of Omicron, combined with the return of the flu for the first time in the pandemic.

The nation’s top epidemiologists sounded a warning against complacency that the Omicron wave could be winding down, saying other public health challenges could take its place.

Much of the mainstream media and government last week gave voice to predictions that the COVID pandemic, which has gripped the nation for more than two years, had reached a high ebb.

But on Thursday Australia’s top experts on infectious diseases were instead forecasting that the virus – or other illnesses – could well ramp up before public health improves.

Chief medical officer Paul Kelly warned the nation may yet face a wave of infections visited by another strain of the virus, such as Omicron and Delta before it.

Chief medical officer Paul Kelly has warned another wave of Omicron may coincide with flu season.

“I do believe that we will have another wave of Omicron in winter,” Professor Kelly said.

“And I think we will have a flu wave in winter for the first time … since the beginning of 2020.

“We have to have realistic expectations about what will happen this year, and probably subsequent years in terms of COVID circulating in the community.

“What I can absolutely say is important is that when influenza vaccine becomes available, we will be pushing hard for that in our most vulnerable groups, which is similar to people who are most vulnerable for COVID, but also includes young children.”

Professor Kelly’s call for greater caution in projecting COVID’s effects and his warning about a potentially deadly flu season were echoed by other epidemiology experts.

Since 2019, experts say Australia has not faced the twin challenges of a virulent flu season alongside a wave of COVID infection.

Until now, the latter has come at the expense of the former, particularly as the public pays greater attention to basic preventive measures such as wearing masks on public transport and regularly washing their hands.

“Every state is doing different things [on COVID],” the University of South Australia’s Professor Adrian Esterman said.

“Territory numbers are still going up, but in South Australia I’m expecting it to come down in about three to four weeks. In other states and territories that’s been coming down but has now almost plateaued out.

“And if people stop wearing face masks, if they stop washing their hands, if they don’t comply with social distancing measures – [then…] unfortunately, because we’d had a very low influenza season for the last two years, it could be a very nasty season.”

Health Minister Greg Hunt on Wednesday announced that as many as 20,000 people in the aged-care system were yet to receive either their first or second COVID vaccination, while as many as 35,000 had opted against having a booster shot.

Professor Esterman said these vaccination figures suggested the nation’s aged-care system – in which more than 550 people have died of COVID since December – was particularly vulnerable to another wave of the virus.

“I think that’s a major, major issue. We should be going into every aged-care home talking to every resident, and the carers and explaining the importance of vaccination,” he told The New Daily.

University of Melbourne Professor Tony Blakely said he believed, with a high degree of certainty, that it was likely the government would again be forced to introduce or revive measures to stop COVID’s spread in the next year.

“To get to where we are, things like not ordering [rapid antigen tests … have] just been an absolute mess of policy failure,” he said.

Instead of thinking in absolutes, Professor Blakely called on the government to start thinking in terms of possible scenarios for the future spread of the virus, in recognition of the shortcomings of predictions of a decline in COVID over summer.

“The worst case [or a future strain] is where it’s as infectious as Omicron, or an even more infectious illness – [and that] puts you in hospital as much as Delta,” he said.

“That’s the worst case scenario we don’t want. And I don’t think it’ll happen  … but we need to plan for it.

“Then there are two lower case scenarios – where it’s as infectious as Omicron, but not too virulent, or that’s not quite as infectious but more virulent, like Delta was. We need to be thinking about those scenarios.”

In response to the threat of a fast-morphing virus, Professor Blakely said the government should be stockpiling preventive public health responses, such as making masks and rapid testing kits widely available in event of another outbreak.

“We’ll get back to normal sometime,” he said.

“I just don’t know whether we’re going to take a year or five years […] hopefully not 10 years.”

Minister Hunt’s remarks about the poor uptake of COVID solutions in aged-care facilities drew criticism on Thursday.

Monash University aged-care expert Professor Joseph Ibrahim questioned the factual basis for Mr Hunt’s claim that vaccine hesitancy was so widespread in the aged-care sector, causing tens of thousands of residents to refuse immunisation.

Dr Ibrahim instead said that it appeared that the minister was guilty of “victim blaming”.

In a statement in response to questions from The New Daily, Mr Hunt defended the health department against claims it had failed to properly conduct its vaccination program or communicate with residents about the benefits of vaccination.

“It is every person’s decision, including senior Australians in aged care, to choose if they are vaccinated,” a spokeswoman said.

“It is not mandatory for an aged-care resident to be vaccinated and therefore it is their choice or those of their family to provide that consent.

“Aged care is helping to lead the nation in uptake of boosters with the 75 per cent uptake from eligible residents who have had their second dose, but we continue to encourage families to provide support and consent for their loved ones to be vaccinated.”

Labor leader Anthony Albanese called on Wednesday for the Aged Care Services Minister, Richard Colbeck, to stand down or face the sack over the government’s handling of the virus’ spread throughout aged-care homes.