Towleroad reported that 30% percent of the men in the study contracted an STI within six months of starting PrEP, while another 50% contracted one within a year of using PrEP. Results of the study are promising, but still there are some questions that should be answered, said the researchers. The study led to US Food and Drug Administration (FDA) approving the pill for use by anyone who wants it, rather than just people who were already HIV positive as a result.

According to the Centers for Disease Control and Prevention, the HIV prevention drug Truvada has shown outputs in terms of reducing the risk of the infection by a whopping 92 percent. And therein lies the problem.

But researchers are working to make the drugs that are available even better: Yesterday, Gilead announced successful results from its phase 3 trial of a new combination pill nicknamed F/TAF to treat HIV, which it’s calling the “next-generation backbone” for HIV treatment.

In a related editorial, Robert M. Grant, MD, MPH, and Kimberly A. Koester, both of the University of California, San Francisco, wrote that the high rate of PrEP uptake within a primary care setting is extremely encouraging, but more work is required to identify and reduce the burden of STIs. “Assuming people are willing to use PrEP and can access PrEP, will they take the medication as directed?”

The study, of 657 patients of San Francisco’s Kaiser Permanente Medical Center, has been hailed as further evidence of the efficacy of PrEP to prevent HIV infection, even among high-risk users.

Not only does the drug pose a risk to those who don’t take it consistently, it’s been criticised in the USA because of the temptation to forgo condoms, which brings with it an increased risk of catching other sexually transmitted diseases.

Since then, these kinds of drugs have done a good job of keeping the virus at bay, but there haven’t been any concrete steps taken toward a potential cure as there have been with other infectious diseases like hepatitis C. Not a single person in the study became infected while on the drug during the study period that included 2.5 years of observation, the Washington Post reported.