Six months....impossible, page-150

Chilling evidence of COVID-19’s potency

Immunologist and Nobel laureate Peter Doherty says COVID-19 is just as deadly as the Spanish flu, and 20 times worse than seasonal flu. And it is far from contained.

By JAMIE WALKER

• From Science
  April 4, 2020
• 5 MINUTE READ
  297

Locked down in his Melbourne home, Nobel laureate Peter Doherty is settling in for the long haul. He says COVID-19 is just as lethal as the Spanish flu that ravaged his parents’ generation, and 20 times worse than seasonal flu.

And it is far from contained.

For Professor Doherty, 79, this is a very intimate fight. The work that earned him a joint Nobel prize for medicine in 1996 underpins the frantic effort at the research institute that carries his name and in labs around the world to find an answer to coronavirus.

But his age and health mean he also has skin in the game. “I will be 80 this year and I’ve got high blood pressure, which is a bad risk factor,” he told The Weekend Australian. “I suppose … that amounts to a personal interest in getting something sooner rather than later with a vaccine.”

Professor Peter Doherty at Geelong's CSIRO facility. Picture: Peter Ristevski

This is where the science intersects with the personal, the pandemic with family life, to separate Professor Doherty and wife Penny from the grandchildren and friends. They worry about their son, Michael, a clinical neurologist working on the frontline at the Swedish Hospital in Seattle, a hotspot in the US.

An immunologist and prolific author, Professor Doherty, one of eight Australians to be honoured with the Nobel and a former Australian of the Year, has been thinking and writing about pandemics for decades, culminating in a 2013 book. His predictions about the course of the outbreak have been prescient. Ten days ago, when infections were doubling every three days, he said social distancing, border closures and partial lockdowns would arrest the rate of spread.

A temporary field hospital set at Ifema convention and exhibition in Madrid, Spain.

This has now happened, to the relief of federal and state authorities. Scott Morrison’s declaration that Australia had shifted to a “suppression” stage in managing the virus came after NSW Chief Medical Officer Kerry Chant said new infections had slowed to 91 to take the state’s count to 2389 cases, nearly half the national total. The Prime Minister said up to 8000 more would have been infected on the trajectory from 12 days ago.

The trend line is still deeply worrying. “We are not out of the woods,” Premier Gladys Berejiklian cautioned on Friday, while in Queensland Annastacia Palaszczuk was adamant the peak was months off and “we are not even on the curve yet”.

Professor Doherty said there was no way of knowing whether the respite was temporary, a lag, and he was concerned about the steady increase in community transmission — cases where the point of infection could not be traced. Dr Chant said 336 of those in NSW were in this category, as were 60 in Melbourne and 30 in Brisbane.

“Some of these (infection numbers) are encouraging but it’s far too early to say where we are at,” Professor Doherty said. “Apart from anything else, there is always a week to two weeks’ lag between the time you are infected and when you start to show symptoms, if you do.

“In a month’s time, we will have a much better picture of the threat level we are experiencing and where it’s going. What we are all hoping now is that it just doesn’t surge.

“New York City has been having a doubling in case numbers every four days, and look at the mathematics of it. It has got an R-nought (basic reproductive number) where one person can infect two or three people. You know the story about the dinner party where one infected person goes and 12 infected people leave? That’s exactly what can happen.”

Professor Doherty said comparisons between the new coronavirus and the reconstructed Spanish influenza virus that killed 50-100 million people globally in 1918-20, 15,000 of them Australian, provided chilling evidence of the potency of COVID-19.

It was as deadly as Spanish flu and 20 times more lethal than seasonal influenza. The closely related strain of SARS that flared in China, some Asian countries and the Canadian city of Toronto in 2003, killing one in 10, and a Middle Eastern variant, MERS, deadly to a third of people it struck, were less infectious and posed a lower pandemic threat.

“The strategy is to hold it down, keep it moderate so it does not overwhelm the health system before we get a vaccine,” he said.

“Of course, the longer it goes on, the more economic damage there is. On the other hand, the longer it goes on, the more likely it becomes we will have good treatments because a lot of drugs are in very short supply, and the closer we will be to a vaccine.

“So it’s a very difficult equation. Our politicians have handled it pretty well. They have made mistakes, they have got things wrong, there are things that shouldn’t have happened, but I wouldn’t give them a black mark overall.”

Here, as overseas, the elderly are at the most acute risk and Professor Doherty is all too aware he is in the firing line. Had he held to his pre-COVID-19 schedule, he would now be at a scientific meeting in the Italian city of Padua, the northern ignition point of the country’s devastating outbreak.

He wonders, however, why young people are succumbing in growing numbers — including a 20-year-old female victim in New York whose death deeply troubles him. “Why? Was there something about her genetic background? Did she get a very high dose of the virus?”

He suspects the hyperactive immune response known as a cytokine storm could be involved. Cytokine proteins are the immune system’s alarm bells — they recruit killer T-cells, the subject of his research recognised by the Nobel committee — to eradicate host cells infected by an invading virus.

Sometimes the defence mechanism misfires. During a runaway coronavirus infection, when the immune system floods the lungs with cytokines, the culling becomes a free-for-all, causing more damage than the virus in the “storm” of inflammation.

In the absence of a vaccine, the idea of “flattening the curve” in Australia is to spread the infection load over a time that can be accommodated by the health system. How long would that take? Professor Doherty said the six-month time frame cited by Mr Morrison was realistic.

House-bound for the duration, he is thinking of penning a chapter to his 2013 tome, Pandemics: What Everyone Needs to Know.

COVID-19 had rewritten the book for science and society, he said. “I now realise, not having lived through a pandemic, what was missing. I may go back and revisit that — if I’m still around after this is all over.”

JAMIE WALKER

ASSOCIATE EDITOR