Heterosexual participants in a daily PrEP study in Botswana apparently adhered at very high rates, and there were no new HIV infections among them. The 229 participants in this open-label extension phase of the TDF2 trial also reported taking fewer sexual risks during the year-long study.

Adherence tests given quarterly to a randomly selected subgroup of 120 people found that these participants had detectable drug in an average of 93 percent of those study visits.

“This study provides a strong indicator that both men and women at risk can adhere to a daily PrEP regimen,” says Allan Taylor, MD, co-author of the paper and a health scientist in the Centers for Disease Control and Prevention’s Division of HIV/AIDS Prevention.