Why it’s impossible to say if the worst of the pandemic is over

There is no evidence that the worst of COVID has passed, Australian virologists say, tempering hopes that the peak of the Omicron wave marked the beginning of the end for the pandemic.

Edward Holmes, a researcher based at the University of Sydney – and among the world’s leading experts on COVID’s genetics, evolution and origin – said it was foolish to attempt to forecast the evolution of a virus that has eluded prediction since its emergence.

COVID-19 cases have been declining nationally for the past two weeks.Credit: Louise Kennerley

“There is no real scientific basis to say the worst is over,” Holmes said. “Every prediction I have made about the evolution of this virus has been wrong. It had fooled us every single time, and I suspect it may have more tricks up its sleeve,” he said.

However, pandemic modellers and epidemiologists are growing increasingly confident that Australia has passed the peak of the winter Omicron wave after the deadliest month of the pandemic to date.

The daily case count has almost halved within two weeks, dropping from almost 50,000 on July 27 to 27,058 on Wednesday.

In NSW, hospitalisations have plateaued, and the rate of COVID-19 notifications per 100,000 people has either decreased or remained stable across all NSW local health districts and all age groups except those aged 10-19, due to students returning to school after the winter holidays.

But the virus was capable of again changing its structure to evade vaccine-induced immunity and continue evolving, Holmes said.

“It has evolved more substantially than anyone imagined; it’s extraordinary,” Holmes said.

At some point, the virus will reach an evolutionary peak, Holmes said. “But is that now? Or next week? Or in a year? We don’t have the answer.”

Associate Professor Stuart Turville, the lead virologist at the Kirby Institute laboratory that is sequencing Omicron variants, echoed Holmes’ reticence to divine the trajectory of the pandemic.

“We didn’t predict, and could never have predicted Omicron,” Turville said.

But he outlined two probable scenarios for the next year of the pandemic. The most probable: Omicron subvariants would remain dominant infections and the population’s hybrid immunity – the protection offered by a combination of previous COVID-19 infection and vaccination – would be effective against any small changes to the virus.

The second scenario is a “wildcard event”: the emergence of a new variant that would be more transmissible than Omicron.

Any new variant is probably “brewing away and becoming battle-hardened” in an immunocompromised person experiencing a prolonged infection, offering little forewarning before spreading through the community, Turville said.

“But the good news is the longer the virus is in the community, the more immunity we gain,” he said. He was optimistic that this would be how the community starts to “corner” the pandemic.

Associate Professor Ian Mackay, a virologist at the University of Queensland, said all signs were pointing to the worst of the pandemic being behind us, “but we won’t know for certain until we can look back in several months’ time and say, ‘Oh, that was the peak.’ ”

“We are addicted to ‘hope-ium’ these days,” Mackay said. “We can’t put money on the hope that new variants will be milder or less severe.”

Professor of infectious diseases at the ANU Medical School Peter Collignon suspects the pandemic has reached its peak in line with the trajectory of the 1918 Spanish flu, which was extremely virulent for the first two to three years before persisting at significantly lower levels for decades.

The proof will be in the coming European and North American winter, and whether they have waves of deaths and hospitalisations, Collignon said.

“I will be proven wrong very quickly if I am wrong. We’ll probably have a pretty good idea by December or January,” he said.

Professor of epidemiology at the Kirby Institute John Kaldor shared that optimism, but said, “we need to maintain our readiness to respond if that prediction is wrong.

“Our COVID planning must be continually adapted, optimised and flexible to respond to whatever comes,” Kaldor said.

“Our early warning system – which relies on global communication networks – worked pretty well with COVID and again with monkeypox, but the world is a tense place now, and it may become more difficult to maintain the level of international co-operation under the circumstances.

“We don’t know how long the vaccines we have now are going to protect us. We will almost certainly need new vaccines and that process needs to be considered carefully,” he said.

Stay across the most crucial developments related to the pandemic with the Coronavirus Update. Sign up for the weekly newsletter.