Microbicide adherence biomarkers, patient uptake challenges focus of symposium

BRUSSELS — Ongoing microbicide safety and efficacy trials should assess key vaginal microbiome bacteria and products should prohibit epithelial disruption and/or inflammation, according to a presenter here at EACS 2013.

In addition, effective use of topical microbicides among vulnerable populations will depend upon partner acceptance, as well as product availability and usability, before sexual intercourse.

“There have been several large epidemiological studies that show that HIV acquisition is increased when the cervicovaginal epithelium is damaged or when there is inflammation,” Janneke van de Wijgert, MD, PhD, of the University of Liverpool in the United Kingdom and the Institute of Infection and Global Health, said in a presentation. “There is also evidence that there is increased HIV acquisition and transmission when the vaginal microbiome is imbalanced or when other sexually transmitted infections are present.”

Wijgert presented data from the Microbicide Safety Biomarkers Study, a prospective cohort study of 430 women in Kenya, South Africa and Rwanda, which examined biomarkers of the cervicovaginal microbiome and inflammation, HIV target cells and reproductive tract infections.

Researchers identified five to six vaginal microbiota clusters dominated by Lactobacillus crispatus, L. iners, as well as three to four clusters with intermediate-to-high bacterial loads of mixtures of anaerobes, including Gardnerella vaginalis, Atopobium vaginae, Prevotella,Clostridium, Dialister, Megasphaera, Sneathia and Mobiluncus spp.

“In addition, we found that vaginal washing after sex was very common, reported by 20% to 60% of women,” Wijgert said. “When asking women to use vaginal microbicide gels, the behavioral practice of vaginal washing after sex should first be taken into account.”

Harriet Langanke

In an accompanying presentation, Harriet Langanke, director of the German Sexuality and Health Foundation, highlighted common obstacles in marketing microbicide products in at-risk populations, including sex workers and those who are HIV-positive.

“To encourage microbicide adherence among these populations, first, the microbicide must be shown to work and the protection must be effective,” Langanke said. “In addition, they need to be easily available and affordable, and produce few unwanted side effects.”

According to Langanke, availability of microbicides through common distributors such as pharmacies or free health clinics, in the same manner as other contraceptives, would significantly enhance social acceptance. Additionally, social recognition of microbicide would improve if the product were more precisely targeted to its intended at-risk populations; for example, a vaginal microbicide gel that also acted as a lubricant.

“Availability is a significant issue, as these products must be easily at hand, at least as easily available as the male condoms, and when it comes to marketing, the product packaging itself has to either be very discreet or evoke a positive image,” Langanke said.

For more information:

CHAARM Satellite Symposium “New Prevention Strategies: The Future of Microbicides”. Presented at: EACS 2013; Oct. 16-19, 2013; Brussels, Belgium.

Disclosure: The researchers reported no relevant financial disclosures.