The highs and lows of great science but profound inequities were front and center on the first official day of CROI 2024. From increasing data on demonstrating the efficacy of DoxyPEP (doxycycline as post-exposure prophylaxis) against some sexually transmitted infections (STIs); and advances in the promise of long-acting PrEP; to data that reinforces the reliability of affordable rapid testing to screen for HIV— Monday showcased vitally important scientific insights.  

Sessions throughout the day, as well as at Sunday’s opening session, reminded all participants that every one of the scientic advances presented at CROI will fail, unless the voices of people who need solutions are heard, amplified and elevated and allowed to lead the discussions.  

Social and behavioral researchers discuss equity with R&D during CROI Community Breakfast Talk   

Monday’s Community Breakfast Club focused on social and behavioral science at CROI – disciplines that have often been marginalized. Speakers pointed out the ongoing need for more of this essential research at CROI. “As much as we try to discover new devices, they need to reach people to have impact. For example, long acting injectables have not worked in real life because we’ve neglected the complexity of rolling [them] out,” said LaRon Nelson, of the Yale School of Nursing. And Sari Reisner, an epidemiologist at the University of Michigan underscored that the outcomes of research are directly tied to the level of involvement from communities whom research is ultimately meant to serve. Don’t miss two more days of programming, sign up here. 

The HIV vaccine search continues 

Barney Graham and Julie McElrath both provided overviews of three decades of HIV vaccine research, and its current status. Graham explained in his opening session Fields Lecture how insights on HIV structure paved the way for rapid understanding of the SARS-COV-2 and resulting vaccines.  

And in her Monday plenary, McElrath summarized the collective knowledge gained from the ten vaccine efficacy trials that have been conducted over the past 20 years. (And check out our new summary graphic of the efficacy trials to date.) She then outlined the key strategies now moving forward–inducing broadly neutralizing antibodies (bNAbs), inducing supplementary CD8+ T-cell responses, and delivering bNAbs as passive protection while learning about vaccine design. Further sessions dug into finer details of early-stage investigations—updates on germline-targeting trials, which use a series of vaccines to prompt the body to develop precursors that lead to bNAbs; and newer adjuvants that enhance the germline targeting strategy 

Even longer long-acting PrEP products? 

A longer-acting injectable cabotegravir for prevention (injectable CAB) has made it through a phase 1 safety and tolerability study. ViiV, the maker of the currently approved injectable cabotegravir, presented findings on a new formulation that could double the time between intramuscular jabs, from two to four months, potentially making it a three-dose annual intervention, instead of six doses.  

Merck also presented data on the safety and pharmacokinetic profile of MK-8527, a product that they are hoping to develop as a monthly pill to prevent HIV. They reported the dose was safe, well-tolerated and sufficient to show anti-viral activity against HIV. The product is currently in a phase 2 trial in several countries globally; and later phase studies would be needed to demonstrate efficacy. Check out our prevention product timeline here. 

DoxyPEP brings down incidence of some STIs. But what else do we need to know? 

Studies corroborated the promise of DoxyPEP to bring down STIs. The DoxyVAC study showed reduced incidence of chlamydia and syphilis and some reduction of gonorrhea. But a vaccine against meningococcal disease (the 4CMenB vaccine) did not show a reduction in gonorrhea incidence, which was seen in an earlier phase of the research. Studies out of San Francisco of men who have sex with men and trans women showed a high demand for DoxyPEP among PrEP users and STI incidence decline. But there remain many questions on DoxyPEP. More data is needed for use among cisgender women, as well as research among communities in low-income countries. Many researchers and advocates are calling for more data on DoxyPEP’s potential to increase antimicrobial resistance (AMR)—which needs more attention as guidelines accelerate DoxyPEP use. Join us in April for an STI Awareness week webinar series where Fabian Kong, Annie Luetkemeyer, and Connie Celum will lead a discussion on AMR, DoxyPEP and more. Sign up here to receive updates, www.avac.org/signup. 

Can we eliminate HPV? 

In what proved to be one of the most elegant plenaries ever delivered, Nelly Mugo from the Kenya Medical Research Institute (KEMRI) provided a remarkable presentation on Shall We Reach Human Papillomavirus Elimination in the Face of Inequity? Her presentation reinforced the essential need to link the best possible science with deep and durable community engagement. And it was quite fitting that she delivered her talk on HPV Awareness Day, when AVAC, TogetHER for Health and partners launched a call to action for global leadership to increase access to lifesaving HPV vaccines for people living with HIV. 

Stay tuned for more updates from AVAC as we track the research and discussion at #CROI2024, and don’t forget to join us Tuesday and Wednesday for the Community Breakfast Clubs.