MELBOURNE (NYTIMES) - If the United States had the same Covid-19 death rate as Australia, about 900,000 lives would have been saved.

For many Americans, imagining what might have been will be painful. But especially now, at the milestone of 1 million deaths in the United States, the nations that did a better job of keeping people alive show what Americans could have done differently and what might still need to change.

Australia offers perhaps the sharpest comparisons with the American experience. Both countries are English-speaking democracies with similar demographic profiles.

In Australia and in the United States, the median age is 38. Roughly 86 per cent of Australians live in urban areas, compared with 83 per cent of Americans.

Yet Australia's Covid death rate sits at one-tenth of America's, putting the nation of 25 million people (with around 7,500 deaths) near the top of global rankings in the protection of life.

Australia's location in the distant Pacific is often cited as the cause for its relative Covid success.

That, however, does not fully explain the difference in outcomes between the two countries, since Australia has long been, like the United States, highly connected to the world through trade, tourism and immigration. In 2019, 9.5 million international tourists came to Australia.

So what went right in Australia and wrong in the United States?

It looks obvious: Australia restricted travel and personal interaction until vaccinations were widely available, then maximised vaccine uptake, prioritising people who were most vulnerable before gradually opening up the country again.

From one outbreak to another, there were also some mistakes. And with Omicron and eased restrictions, deaths have increased.

But Australia's Covid-19 playbook produced results because of something more easily felt than analysed at a news conference.

Dozens of interviews, along with survey data and scientific studies from around the world, point to a lifesaving trait that Australians displayed from the top of government to the hospital floor and that Americans have shown they lack: trust, in science and institutions, but especially in one another.

When the pandemic began, 76 per cent of Australians said they trusted the healthcare system (compared with around 34 per cent of Americans), and 93 per cent of Australians reported being able to get support in times of crisis from people living outside their household.

In global surveys, Australians were more likely than Americans to agree that "most people can be trusted" - a major factor, researchers found, in getting people to change their behaviour for the common good to combat Covid-19.

But of greater import, interpersonal trust - a belief that others would do what was right not just for the individual but for the community - saved lives. Trust mattered more than smoking prevalence, health spending or form of government, a study of 177 countries in The Lancet recently found.

Government: Moving quickly behind the scenes

Mr Greg Hunt had been Australia's health minister for a couple of years when his phone buzzed Jan 20, 2020. It was Dr Brendan Murphy, Australia's chief medical officer, and he wanted to talk about a new coronavirus in China.

Dr Murphy said there were worrisome signs of human-to-human transmission.

"I think this has the potential to go beyond anything we've seen in our lifetime," Dr Murphy said. "We need to act fast."

The next day, Australia added the coronavirus, as a threat with "pandemic potential," to its biosecurity list, officially setting in motion the country's emergency response.

Mr Hunt briefed Prime Minister Scott Morrison, visited the country's stockpile of personal protective equipment and began calling independent experts for guidance.

The first positive case appeared in Australia on Jan 25. Five days later, when the Centres for Disease Control and Prevention confirmed the first human transmission of the virus in the United States, President Donald Trump downplayed the risk.

The same day, Mr Hunt struck a more practical tone. "Border, isolation, surveillance and case-tracing mechanisms are already in place in Australia," he said.

Less than 24 hours later, on Feb 1, Australia closed its border with China, its largest trading partner. On Feb 3, 241 Australians were evacuated from China and placed in government quarantine for 14 days.

A full border closure followed. Hotels were contracted to quarantine the trickle of international arrivals allowed in. Systems for free testing and contact tracing were rolled out, along with a federal programme that paid Covid-affected employees so they would stay home.

Healthcare: Sharing the burden

The outbreak that many Australians see as their country's greatest Covid test began in late June 2020, with a breakdown in Melbourne's hotel quarantine system. The virus spread into the city and its suburbs from guards interacting with travellers, a government inquiry later found, and within a few weeks, daily case numbers climbed into the hundreds.

At Royal Melbourne, a public hospital built to serve the poor, clusters of infection emerged among vulnerable patients and workers.

"We recognised right away that this was a disaster we'd never planned for, in that it was a marathon, not a sprint," said Dr Chris Macisaac, Royal Melbourne's director of intensive care.

In mid-July, dozens of patients with Covid were transferred from nursing homes to Royal Park, a satellite facility for geriatric care and rehabilitation. Soon, more than 40 per cent of the cases among workers were connected to that small campus.

Dr Kirsty Buising, an infectious disease consultant at the hospital, began to suspect - before scientists could prove it - that the coronavirus was airborne. In mid-July, on her suggestion, Royal Melbourne started giving N95 masks to workers exposed to Covid patients.

In the United States, hospital executives were lining up third-party PPE vendors for clandestine meetings in parking lots. Royal Melbourne's supplies came from federal and state stockpiles, with guidelines for how distribution should be prioritised.

In New York, a city of 8 million people packed closely together, more than 300 healthcare workers died from Covid by the end of September, with huge disparities in outcomes for patients and workers from one hospital to another.

In Melbourne, a city of 5 million with a dense inner core surrounded by suburbs, the masks, a greater separation of patients and an intense 111-day lockdown that reduced demand on hospital services brought the virus to heel. At Royal Melbourne, not a single worker died during Australia's worst institutional cluster to date.

Society: Complying and caring

When Australians are asked why they accepted the country's many lockdowns, its once-closed international and state borders, its quarantine rules and then its vaccine mandates for certain professions or restaurants and large events, they tend to voice a version of the same response: It's not just about me.

The idea that one's actions affect others is not unique to Australia, and at times, the rules on Covid stirred up outrage.

"It was a somewhat authoritarian approach," said Dr Greg Dore, an infectious diseases expert at the University of New South Wales in Sydney. "There were lots of mandates, lots of fines for breaching restrictions, pretty heavy-handed controlling, including measures that were pretty useless, like the policing of outdoor masking."

But, he added, the package was effective because the vast majority of Australians stuck with it anyway.

"The community coming on board and remaining on board through the tough periods of 2020 and even into 2021 was really, really important," Dr Dore said.

Now, more than 95 per cent of Australian adults are fully vaccinated - with 85 per cent of the total population having received two doses. In the United States, that figure is only 66 per cent.

The arrival of the Omicron variant, which is more transmissible, has sent Australia's case numbers soaring, but with most of the population inoculated, deaths are ticking up more slowly.

"We learned that we can come together very quickly," said Ms Denise Heinjus, Royal Melbourne's executive director for nursing, whose title in 2020 was Covid commander. "There's a high level of trust among our people."