Pre-exposure prophylaxis, better known as PrEP, is a pill that if taken daily is almost 100% effective at eliminating the spread of HIV. It's widely available in the U.S. but much harder to access in Australia. Here's the how, what and why of PrEP.
1. It's not widely available here.
Gilead, the company that makes PrEP, has applied to Australia's Therapeutic Goods Administration (TGA) to make the pill available here. But it's a long process, meaning the pill, which is marketed as Truvada, won't be available here until at least mid-2016.
From there it will need to make its way onto the Pharmaceutical Benefits Scheme, which will significantly reduce the cost of the drug. But that won't happen until at least 2017.
2. But that doesn't mean you can't access it.
It's perfectly legal to obtain PrEP in Australia, it's just not that easy. If a doctor thinks you're suitable to take PrEP, he or she can prescribe it to you and you can pay the full, unsubsidised price for it or order a generic version online from overseas. But this can be prohibitively expensive.
To buy it in Australia would cost around $13,500 a year, and to order it online can cost more than $100 a month. Ordering online also comes with risks. Will you get what you paid for?
The high cost disproportionately effects those most at risk of contracting HIV - gay men and transgender women on low incomes, sex workers, and injecting drug users.
3. More and more studies say PrEP is highly effective.
Dr Bob Grant, who has been studying HIV and the efficacy of PrEP for over 30 years, recently published a landmark study showing the PrEP is 99% effective when taken daily. Other studies have put the drug's efficacy rate at 92%.
"PrEP works when it's taken," he recently told a community forum in Sydney. "I've never seen an HIV infection from someone taking it four times a week or more."
In San Francisco, the epicentre of PrEP use in the U.S., HIV infection rates have reduced by 30% in the last two years as PrEP use increases. (This isn't entirely attributable to PrEP, but the drug certainly plays a large part).
4. Those who need it most are the ones most likely to take it.
For a long time, one of the things holding PrEP use back was the idea that people wouldn't be willing to take a pill each day, but new studies show that's not really true.
Studies have found that adherence to daily, oral anti-retroviral medication is completely feasible.
As Dr Grant says, "The people who say it's impossible take a pill each day to prevent something are always men."
Dr Grant's research has found that those who engage in the 'riskiest' sexual practices, (such as condomless sex) are among the most likely to take up PrEP.
5. It's not popular with everyone.
In the U.S. as PrEP use increased, so did opposition to the drug. Prominent HIV activist Michael Weinstein has labelled it a "party drug" and the term "Truvada whores" has been used to describe gay men who might be tempted to engage in riskier sexual activities because they felt better protected from HIV. This in turn led to a stigmatisation of PrEP users, who were less likely to take up the drug.
But this hasn't really occurred in Australia.
"We haven't seen very much of that to date which is fantastic," says James Gray, the Acting Director of HIV and Sexual Health at ACON, Australia's largest LGBTI health organisation.
"It's really important to frame PrEP use as being something that someone does to be responsible about their sexual health. There have been some concerns about the impact of condom use - because we do have high rates of condom use in Australia - and there's also been worries about other sexually transmitted infections. But thankfully to date the response in Australia has been pretty positive."
6. It's not just for gay men.
Most PrEP users are gay men or other men who have sex with men (MSM), which makes sense because in the western world, where PrEP is more widely available, new HIV infections are most likely to occur in MSM. But PrEP can also be used by sex workers or women whose partners are HIV+, but are trying to conceive a child.
There are 35 demonstration projects worldwide, ranging from injecting drug users in Thailand to heterosexual couples where one partner is HIV+ in Nigeria and transgender sex workers in India.
In Botswana, a study of 1,219 HIV-uninfected male and female volunteers found that those who took the drug saw their risk of HIV infection reduced by 78%.
7. Some Australians are taking PrEP now.
There are clinical studies underway into the efficacy of PrEP in NSW, Queensland and Victoria. The NSW and Victorian studies are already full and the Queensland one is filling up fast.
In NSW, 300 men have been taking PrEP for around a year. The study conducted by the Kirby Institute with the NSW department of health is due to make its first findings by the end of the year.
One of the study's participants, 47-year-old Jyan, told BuzzFeed News that PrEP has had nothing but positive effects for him. Jyan is in an open relationship, and says PrEP makes him feel much safer.
"I didn't realise how much anxiety I had around sex until I started taking PrEP," he says. "For the first few days [of taking the drug] there were some minor side effects, but overall I'm really pleased I started taking PrEP."