HIV drug resistance and infection can be prevented by giving at-risk people medications before they're exposed, in a process known as pre-exposure prophylaxis (PrEP), new research from UCLA suggests.
"By cutting down infections, the PrEP programs will decrease the number entering treatment programs, and therefore, fewer individuals will acquire drug resistance," Sally Blower, director of the university's Center for Biomedical Modeling and a professor at the Semel Institute for Neuroscience and Human Behavior, said in a statement. "So introducing PrEP around the worst treatment programs will have the most impact on reducing resistance."
Although Blower's team feared that use of PrEP would lead to high levels of drug resistance, her research found that wasn't the case. Researchers used computer modeling and found that a PrEP prevention program used alone, or HIV treatment used alone, could increase drug resistance. But resistance actually decreased when used together.
"This was a very big surprise," said Blower. "We found that this counterintuitive effect will only occur if adherence to the PrEP prevention program, where individuals have to take a daily pill, is very high. This counterintuitive effect occurs when the beneficial effect of PrEP in preventing infections is so great that it overcomes both its own detrimental effect on increasing resistance and the detrimental effect of current HIV treatments on increasing resistance."
Botswana, which the team used for their modeling, has the best health care system in Africa, and is likely to be the first to implement PrEP. But researchers said that for the biggest decrease in resistance, PrEP should target countries with the least-successful programs and where resistance is already high.
The study appears in the current online edition of the journal Scientific Reports.
