CDC’s Dr. Mermin and Dr. Brooks Share Mpox and HIV Prevention Highlights from CROI 2023

Content From: HIV.govPublished: February 24, 20234 min read


As the 2023 Conference on Retroviruses and Opportunistic Infections (CROI) wound to a close this week, spoke with CDC’s Dr. Jono Mermin and Dr. John Brooks about some of the research highlights that stood out to them, including studies on mpox, HIV PrEP, STI post-exposure prophylaxis, and long-acting HIV treatment. Dr. Mermin is Director of CDC’s National Center for HIV, Viral Hepatitis, STD, and TB Prevention (NCHHSTP) and Dr. Brooks is the Chief Medical Officer in CDC’s Division of HIV Prevention. Both Dr. Mermin and Dr. Brooks played leading roles in CDC’s response to the mpox outbreak in 2022. Watch our conversationExit Disclaimer with them below:

Mpox Research Debuts at CROI 2023

Dr. Brooks observed that the conference had incorporated research on mpox this year for the first time. Among the studies and discussions that stood out to him were ones on the differential impact of mpox on people with HIV, particularly those with untreated, advanced HIV. The evidence demonstrates that the latter experience more severe and longer cases of mpox, which can be deadly for some individuals. He also noted that studies underscored the effectiveness of the mpox vaccine and encouraged individuals who may be at risk of acquiring mpox to be sure that they’ve received both doses of the mpox vaccine.

Dr. Mermin and Dr. Brooks also discussed the importance of efforts to get mpox vaccines and treatment to the populations most affected. They highlighted vaccine equity efforts undertaken at CDC to make mpox vaccines available at a variety of events and venues where individuals who may be at risk gather, an effort that will soon expand with support from the CDC Foundation. They also encouraged healthcare providers and others in the HIV services community—including HIV care providers, sexual health and STD clinics, and community-based organizations—to integrate mpox education, vaccination, and treatment into their work. Clinicians who diagnose a patient with mpox can invite them to join the STOMP trialExit Disclaimer, which is an NIH-funded clinical trial to evaluate the effectiveness of the antiviral tecovirimat, also known as TPOXX, for mpox treatment.

Studies on HIV PrEP, STI PEP, and Long-Acting ART for People Not Virally Suppressed

Dr. Mermin highlighted a review of data on daily oral HIV PrEP for women presented by Dr. Jeanne Marrazzo of the University of Alabama at Birmingham. She and her colleagues analyzed data from 11 demonstration projects and studies of daily oral PrEP (emtricitabine/tenofovir disoproxil fumarate) involving more than 6,000 cisgender women in six countries. Their analysis concluded that daily oral PrEP has high effectiveness in cisgender women with consistently high adherence. They also concluded that adherence support should be provided to help women use oral PrEP effectively to achieve high levels of protection.

Dr. Mermin also discussed a clinical trial on the effectiveness of a 200 mg dose of the antibiotic doxycycline taken as post-exposure prophylaxis to prevent sexually transmitted infections (STIs) within 72 hours of condomless sex. The approach is known as DoxyPEP. The study was presented by Dr. Jean-Michel Molina of the University of Paris Cité and involved 500 men who have sex with men who were using HIV PrEP and had a recent history of a bacterial STI. The use of Doxy-PEP was shown to be effective at reducing chlamydia, gonorrhea, and syphilis. The study also found that two doses of meningococcal B vaccine reduced the incidence of gonorrhea in the study participants. (See Dr. Carl Dieffenbach’s discussion of this same studyExit Disclaimer in another conversation from CROI.)

Finally, Dr. Mermin and Dr. Brooks highlighted a study demonstrating that individuals with HIV who were not virally suppressed, or even on antiretroviral therapy (ART), many of whom also experienced unstable housing, mental illness, and/or substance use disorders, can achieve and maintain a suppressed viral load with long-acting injectable ART and wrap-around services that help them address the challenges that interfered with their ability to take daily ART. The findings from this NIH-supported study were presented by Dr. Monica Gandhi of the University of California San Francisco. Read more about the study here. (See Dr. Laura Cheever’s discussion of this same study in another conversation from CROI.)

About CROI

CROI is an annual scientific meeting that brings together leading researchers and clinical investigators from around the world to present, discuss, and critique the latest studies that can help accelerate global progress in the response to HIV and other infectious diseases, including COVID-19 and mpox. The 2023 meeting took place in Seattle. More than 3,400 HIV and infectious disease researchers from 72 countries participated in person or virtually and over 900 scientific abstracts were presented. Visit the conference websiteExit Disclaimer for more information; abstracts, session webcasts, and e-posters will be published there for public access 30 days after the conference concludes.

More HIV Research Updates from CROI on shared additional video interviews from CROI 2023 with NIH’s Dr. Carl Dieffenbach and HRSA’s Dr. Laura Cheever. You can find them on’s social media channels and re-capped here on the blog. Be sure to watch, comment, and share!