MELBOURNE, Australia — It took universal health care, political will and a health campaign designed to terrify the public, but nearly four decades into the H.I.V. crisis, Australian researchers say the country is on a path toward making transmissions of the virus vanishingly rare.
The fight is not yet won, the experts caution, and the last stretch of disease eradication efforts is often the toughest. But in the past five years, the number of new infections with the virus has dropped by almost a quarter in Australia, with higher declines among gay and bisexual men, according to a report released last week by the Kirby Institute, an infectious disease research center in the state of New South Wales.
In 2018, just 835 H.I.V. diagnoses were recorded nationally. At their peak, in 1987, there were 2,412.
The most recent advance in Australia’s battle against the virus, which is seen as a model around the world, is the rapid adoption of a drug regimen known as PrEP. Under the regimen, patients typically take a daily pill, which — even without the use of condoms — is close to 100 percent effective at preventing contraction of H.I.V., experts say.
In Australia, more than 40 percent of gay men considered to be most at risk of infection are on PrEP, according to the Kirby Institute. Adoption rates are lower in the United States: While the Centers for Disease Control and Prevention say that more than 1.1 million Americans need PrEP, one group that tracks data on the regimen says that only about 270,000 are on it. The C.D.C. is expected to release new figures on Thursday.
“Provided we don’t take our foot off the pedal, we stand a chance of eliminating H.I.V. by 2030” in Australia, said Andrew Grulich, an author of the Kirby Institute report and a professor of epidemiology at the University of New South Wales.
Truvada, which is used for H.I.V. treatment and PrEP — the abbreviation stands for pre-exposure prophylaxis — was formally added as a preventive medication to the list of pharmaceuticals available at subsidized rates under Australia’s universal health care program in April 2018.
Since then, any permanent resident or citizen of Australia has been able to get the pill, or its generic alternative, by obtaining a prescription from a doctor and purchasing it from a pharmacy. For these people, it usually costs about 40 Australian dollars, or $28, per month.
CreditChristina Simons for The New York Times
“If you have a universal health care system like Australia does, then getting yourself on PrEP is easy, whether you are unemployed or a millionaire,” Dr. Grulich said.
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Truvada was developed in the United States and first approved for use in H.I.V. prevention there in 2012. But the medication has been slow to gain a foothold in the country because of a variety of obstacles, including what Dr. Robert Grant, a professor of medicine at the University of California, San Francisco, called a “byzantine system” that many patients find impossible to navigate.
Some cities, including New York and San Francisco, have made strides toward providing free or subsidized access to PrEP, with corresponding declines in H.I.V. diagnoses. Gilead Sciences, the maker of Truvada, also recently promised to supply 200,000 uninsured patients with the pill.
And as of last month, most private health insurers are now required to offer the medication — which has a list price of about $2,100 per month — at no out-of-pocket cost to their policyholders.
But in poorer and more rural areas, patients and even doctors may not have heard of Truvada, said Dr. Grant, who led the development of PrEP. Costs for doctor’s appointments themselves might be prohibitive, or patients may be unaware of the assistance available to them, he said. In addition, Truvada has been stigmatized in some parts of the United States as promoting promiscuity, creating barriers to access and use.
Bill Bowtell, a strategic health policy consultant who helped lead Australia’s response to the AIDS crisis and continues to advise governments on H.I.V. policy, said the system in the United States “could not be set up better to maintain a continuing H.I.V. and AIDS pandemic.”
Rates of H.I.V. have remained largely unchanged in the United States in recent years: They continue to rise among gay and bisexual Hispanic and Latino men, and have not improved among gay and bisexual African-American men, according to figures from the Centers for Disease Control and Prevention.
Among these minority communities, PrEP adoption is minimal: They account for two-thirds of the at-risk population, but only a small fraction of prescriptions, a study last year showed.
Australia is also not immune to disparities in H.I.V. prevention and treatment.
While there has been rapid progress among Australian-born urban gay men, the rates of the virus among Aboriginal and Torres Strait Islander Australians have remained stable. These groups, along with overseas-born gay men and those who live in rural areas, are less likely to make use of PrEP or H.I.V. testing, researchers say.
Despite these challenges, Australia has among the lowest H.I.V. prevalence rates in the world: About 0.1 percent of the population carries the virus, according to a separate 2018 report from the Kirby Institute. The figure in the United States is four times as high.
Rates are far higher in sub-Saharan Africa, where about 4 percent of adults carry the virus, accounting for almost 70 percent of those living with H.I.V. worldwide, according to the World Health Organization.
In Australia, the fast adoption of PrEP is just the latest step in a comprehensive response that dates back to the 1980s.
In its early stages, it involved, among other things, the providing of free condoms and clean needles, as well as a controversial public health advertisement in which the Grim Reaper emerged from a cloud of smoke to strike down victims with a bowling ball. All of those measures were championed by the country’s prime minister at the time, Bob Hawke, whose own daughter struggled with heroin addiction.
Australia’s current system of universal health care, known as Medicare, was introduced in 1984, two years after the country’s first H.I.V. diagnosis. “When we were then confronted with the greatest public health crisis of our times, we were able to deploy resources,” said Mr. Bowtell, the health policy consultant.
In the United States, he said, the reaction to H.I.V. and AIDS in the early years took on religious and moral overtones — some people described the disease as a punishment from God — and the administration of President Ronald Reagan was slow to act. Australia, by contrast, mostly managed to keep H.I.V. from becoming a moral or a political issue, Mr. Bowtell added.
In 2015, as PrEP was first emerging in Australia, an activist group in Melbourne put up posters with an expletive encouraging people to have sex without condoms. Activists and PrEP users say they accurately captured the sense of freedom that Truvada has granted.
People living with H.I.V. have long carried the burden of preventing its spread, said Mark Binette, 34, a physiotherapist from Melbourne who is on PrEP. The regimen, he added, offered a way to help shift that responsibility.
PrEP is not the only reason for declines in H.I.V. transmission: In many cases, antiretroviral drugs reduce the presence of the virus in patients’ bodies to levels so low that they will not pass it on to others. But to ever fully eliminate H.I.V. transmission, a vaccine will most likely be needed, scientists say.
Also crucial is ending the stigma attached to the virus, which can stop people from seeking access to prevention measures and treatment, said Dr. Edwina Wright, a physician and clinical researcher at the Alfred Hospital at Monash University in Melbourne.
“It’s not all biomedical,” Dr. Wright said. “If we could have a vaccine in the short term against stigma,” she added, “that would be great.”