By the time he was 25, Ed Moreno was preparing to die.

He imagined a painful and undignified end — a fate he saw other gay men suffer.

He was diagnosed with human immunodeficiency virus (HIV) in 1990.

"They gave me five years to live," he said.

"AIDS was killing people in a very ugly way … [there were] disfigurements, painful deaths."

It was around the height of the AIDS epidemic that was terrifying the world.

Back then AIDS (acquired immunodeficiency syndrome) and its precursor, HIV, were effectively a death sentence.

"Telling my parents was probably the hardest thing I've ever had to do," Mr Moreno said.

Mr Moreno resigned himself to the "numbing" thought he would be lucky to reach 30, but his sights were set on going "out with a bang".

The American moved from his home town of Santa Fe to Miami to party away what remained of his relatively short life.

"I decided I was going to live large," he said.

The anti-retroviral revolution

However, by the mid-1990s, major medical advances meant that AIDS was no longer a death sentence: it was a chronic condition which could be managed with multiple anti-retroviral drugs.

Mr Moreno started treatment, which at the time involved a complicated cocktail of medications with painful side effects.

Still it wasn't until 2003, more than a decade after his diagnosis, that he contemplated one day experiencing old age.

"It took me a long time to realise I wasn't actually going to die," he said.

"It's kind of feel like I lost those 13 years."

Living under the dark cloud

In recent years, HIV treatment has been simplified down to a pill a day.

It is now shown that with effective and sustained treatment, the virus cannot be detected by standard blood tests or transmitted during sex.

More than 26,000 Australians were living with HIV in 2016, according to the Kirby Institute at the University of New South Wales.

Of them, more than 90 per cent had an undetectable viral load.

"A person living with HIV like myself, takes my medication every day," said Nic Holas from The Institute of Many.

"That one pill stops HIV in its tracks, it stops the virus replicating."

The organisation is behind a new push to end HIV stigma.

The U=U campaign — which stands for "undetectable equals untransmittable" — involves Mr Moreno and four others sharing their HIV experiences.

Mr Moreno is now 53 and calls Melbourne home. He personally knows the impact of outdated views on HIV.

"I had an experience not too long ago of someone wanting to keep my cutlery and cups separate," he said.

The gap between science and perception extends to those with the virus, Mr Holas added.

"We've been living under a very dark cloud of HIV for many decades," he said.

"HIV positive people hear it [the U=U message] and [say], 'Oh, but what if?'"

Mr Holas stressed the U=U campaign was grounded in strong scientific research.

"Some of the greatest scientific minds in the field, at an international level, have endorsed the U=U statement," Mr Holas said.

"There is effectively zero risk of transmission, so don't worry about it."

HIV overrepresented in Indigenous Australians

While the overall rate of HIV infections has remained relatively stable in Australia, Indigenous Australians are still overly represented in the figures.

Aboriginal man Davey Thompson, 26, does not have HIV — but got involved in the campaign to help spread the U=U message.

"I grew up with a funny, outdated, stereotypical view of the virus and how it affects people," he said.

"I had to unlearn a lot of that when I moved to the city."

The campaign came as HIV prevention drug PrEP or pre-exposure prophylaxis was made available with a taxpayer subsidy.

From Sunday, the over-the-counter cost has been slashed to $39.50 a month or $6.40 for those with a concession card.

About 15,000 Australians are already taking PrEP through trials funded by state governments and health organisations.

Federal Health Minister Greg Hunt accepted the advice of a panel of experts who in February recommended adding the drug to the Pharmaceutical Benefits Scheme.

For those like Mr Moreno, medical and social changes affecting the gay community have come faster than "ever imagined".

"I think this is how we are going to end HIV," he said.