Researchers have found that taking an anti-HIV pill right before sex and for a few days after can help protect against the human immunodeficiency virus (HIV), reports Reuters.
The US Food and Drug Administration approved the pill, called Truvada, in 2012. Truvada is supposedly for pre-exposure prophylaxis (PrEP) against HIV, the virus responsible for AIDS. The US Centers for Disease Control and Prevention say that uninfected people who take the drug can reduce their risk of getting HIV during sex by over 90%.
In the ANRS IPERGAY trial, 362 gay and bisexual men were randomly given Truvada “as needed,” instead of daily, acting as an inactive dummy pill. The rest took a placebo. The individuals taking Truvada showed an 86% decrease in new HIV infections compared to those on placebos. After this phase ended in 2014, the researchers gave all participants Truvada.
After around 18 months, the risk of HIV among the trial participants had fallen by 97%, compared to results with the dummy pill in the previous phase.
Dr. Jean-Michel Molina of Hospital Saint-Louis in Paris, a lead researcher in the study, told Reuters that the results were amazing.
For the trial, individuals took two pills two to 24 hours before having sex. They then took a tablet 24 hours later, and a second tablet 48 hours later. If the participants engaged in continuous sexual activity, they were to take a pill each day and a pill for the next two days after last having sex.
During the initial part of the trial, the study recorded 6.6 new infections per year among every 100 people taking the dummy pill, compared to only 0.91 new infections per year among every 100 people taking PrEP. When all the participants started taking PrEP, the rate of new infections dropped to 0.19 per 100 people yearly.
Molina was not surprised that infection rates dropped when people started using PrEP regularly. He said,
Participants knew the efficacy of on demand PrEP and were more inclined to use it as recommended.
Molina and fellow French and Canadian researchers spoke at AIDS 2016 in Durban, South Africa this Wednesday, reporting that only one person acquired HIV in the last phase of their trail. The person had not been taking PrEP in months and no levels of the drug were detected in his blood upon diagnosis.
In France, Molina said, 66% of people take PrEP on demand. “I think it is an interesting alternative for people who did not want to commit to a daily pill,” he said.
The trial results are only applicable to men who have intercourse with other men, but Molina said that studies in other populations are underway. The team also noted that the use of condoms declined in the last phase of the trial, primarily among the men who had previously said they would use condoms.
Dr. Bruno Spire of INSERM in France, also a researcher on the trial, said that condoms were not often used by participants in the trial, and the protection came mainly from PrEP.
Without condoms, individuals are still susceptible to other sexually transmitted infections, but these are generally treatable, Spire said. He added that the rates of other STIs in the study remained steady, neither increasing nor decreasing.
Spire likewise told Reuters that it might be better to educate people on when they should decide to use PrEP, while others might be better off having the pill as part of their daily regimens. He also said that the results of their study cannot predict what would happen in real life, when people take pills on their own outside of any clinical trials.
When the results of the trial were made public last year, the CDC announced that it “continues to recommend daily dosing of PrEP and urges people at substantial risk for HIV infection and their health care providers to continue to follow current CDC guidelines.”
