New NIAID-supported science presented at the 2024 HIV Research for Prevention (HIVR4P) conference in Lima, Peru features a breadth of HIV discovery and translational findings and enriches the evidence base on HIV pre-exposure prophylaxis (PrEP) within the context of reproductive health. Select Institute-supported science highlights are summarized below. Full HIVR4P abstracts are posted on the official conference Web site.

Using PrEP Modalities Alongside Contraception and in the First Trimester of Pregnancy

The monthly dapivirine vaginal ring for HIV prevention was safe in cisgender women who used the ring during early pregnancy and then discontinued use as soon as they learned that they were pregnant. In a pre-licensure open-label study of the dapivirine vaginal ring, participants stopped using it if they became pregnant because ring use during pregnancy was beyond the scope of the study. Pregnant study participants remained enrolled after discontinuing the ring and were monitored for safety throughout their pregnancies. An analysis of data from 72 pregnancies found that there were no notable adverse effects among the participants or their infants when the ring was used in early pregnancy. These findings add to the growing evidence that the dapivirine vaginal ring is safe to use throughout pregnancy. Data presented from another study previously confirmed the safety of the ring when participants initiated use during the second trimester and continued to use it until delivery.

An analysis from the Phase 3 study of long-acting injectable cabotegravir (CAB-LA) PrEP in cisgender women found the drug did not interact with long-acting reversible contraceptive (LARC) drugs. A subset of study participants taking the LARCs etonogestrel, medroxyprogesterone acetate or norethindrone provided additional blood samples so that the study team could analyze how taking LARCs together with CAB-LA or oral PrEP with tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) could affect the levels of the antiretroviral drugs and contraceptive agents in the body. There were no drug interactions between CAB-LA and any of the LARCs. Interaction between TDF/FTC and LARCs could not be determined because adherence to TDF/FTC was low in the participating cohort. CAB-LA and TDF/FTC were previously shown to be safe for use in pregnancy. 

Early-Stage Findings on HIV Vaccines to Produce HIV Broadly Neutralizing Antibodies

Several studies of germline targeting—a promising HIV vaccine strategy that stimulates the immune system to generate antibodies capable of neutralizing diverse HIV strains—reported results to inform the next stages of vaccine development. Findings in people and animal models showed that several immunogens—molecules used in a vaccine to elicit a specific immune system response—began to prompt immune responses that could generate HIV broadly neutralizing antibodies (bNAbs). In one study of 53 participants without HIV, a vaccine containing a nanoparticle immunogen called 426.mod.core-C4b was safe at multiple dosing levels and appeared to generate B cells capable of producing bNAbs if stimulated further. These findings are informing the development of more advanced HIV vaccine concepts involving the 426.mod.core-C4b immunogen. 

Understanding the HIV Reservoir and HIV Remission Off Antiretroviral Therapy

HIV is difficult to cure because the virus is skilled at “hiding” in the body and can reappear in the blood stream shortly after antiretroviral therapy (ART) is stopped. These hiding places, called reservoirs, are unaffected by ART. NIAID-supported scientists are exploring strategies to clear HIV and its reservoirs from the body or to reduce HIV to levels that can be suppressed by a person’s own immune system. A new small study found that monocytes—a type of white blood cell—expressing a gene called interleukin 1 beta (IL1B) are associated with smaller HIV reservoirs after a person acquires HIV. Further understanding of the influence of IL1B on HIV reservoir size could guide future novel HIV remission strategies.

Clinical trials and animal studies of HIV remission approaches reported outcomes of interventions designed to maintain HIV viral suppression or remission after ART was paused. When ART is paused in an HIV remission study it is called an analytical treatment interruption (ATI). In one study, researchers infected 16 infant monkeys with the simian version of HIV (SHIV), then placed them into three different treatment groups, each including ART with various combinations of the investigational HIV drug leronlimab and the HIV bNAbs called PGT121-LS and VRC07-523-LS. After 27 weeks of treatment, the research team conducted an ATI and observed outcomes by treatment group. Animals that received ART and both HIV bNAbs experienced rapid rebound of detectable SHIV. Two of 6 animals that received ART and leronlimab remained free of detectable virus through 20 weeks after ATI. All of the animals that received ART, leronlimab and the two HIV bNAbs remained free of detectable virus at the time of abstract submission, 15 weeks after ATI. Monitoring and assessment of monkeys’ SHIV reservoirs is ongoing, and further studies are warranted to understand the effects observed, according to the authors.

Novel PrEP Implant Technology 

Available PrEP methods currently include oral pill, long-acting injectable, and controlled release vaginal ring formulations. A novel refillable controlled-release antiretroviral drug (ARV) implant was found to be safe and capable of delivering one or more ARVs. The implant, placed subdermally—just under the skin—was examined in monkeys and demonstrated that it could provide sustained release of the investigational ARVs islatravir and MK-8527 as well as the lenacapavir, which is licensed for ART and being studied for PrEP, and bictegravir and dolutegravir, both licensed for ART. Implants containing islatravir were evaluated for efficacy as PrEP and found to completely protect the animals from SHIV challenge—direct administration of the virus vaginally and rectally—through 29 months. The implant is being studied for delivery of ARVs for PrEP and ART.

HIV clinical research builds upon basic science discoveries, preclinical studies, and consultations with communities affected by HIV. Further, clinical research relies on the dedication of study participants and the people who support them. NIAID is grateful to all who contribute to advancing HIV research.

References

P Ehrenberg et al. Single-cell analyses reveal that monocyte gene expression impacts HIV-1 reservoir size in acutely treated cohorts. HIV Research for Prevention Conference. Tuesday, October 8, 2024.

W Hahn et al. Vaccination with a novel fractional escalating dose strategy improves early humoral responses with a novel germline targeting HIV vaccine (426.mod.core-C4b): preliminary results from HVTN 301. HIV Research for Prevention Conference. Wednesday, October 9, 2024. 

N. Haigwood et al. Short-term combination immunotherapy with broadly neutralizing antibodies and CCR5 blockade mediates ART-free viral control in infant rhesus macaques. HIV Research for Prevention Conference. Wednesday, October 9, 2024.

M Marzinke et al. Evaluation of potential pharmacologic interactions between CAB-LA or TDF/FTC and hormonal contraceptive agents: a tertiary analysis of HPTN 084. HIV Research for Prevention Conference. Thursday, October 10, 2024.

A Mayo et al. Pregnancy and infant outcomes among individuals exposed to dapivirine ring during the first trimester of pregnancy in the MTN-025/HOPE open-label extension trial. HIV Research for Prevention Conference. Thursday, October 10, 2024.

F Pons-Faudoa et al. Drug-agnostic transcutaneously-refillable subdermal implant for ultra-long-acting delivery of antiretrovirals for HIV prevention. HIV Research for Prevention Conference. Wednesday, October 9, 2024.

Discovery, Development and Delivery for an Increasingly Interconnected HIV Landscape 

By Carl Dieffenbach, Ph.D., director, Division of AIDS, NIAID

This blog is the third in a series about the future of NIAID's HIV clinical research enterprise. For more information, please visit the HIV Clinical Research Enterprise page.

The NIAID HIV clinical research enterprise has celebrated important scientific advances since awards were made to the current networks in 2020. These achievements include the culminating steps in decades of research that led to approval of the first generation of long-acting medications for HIV prevention—a milestone that raises the standard for any future antiretroviral drug development to levels unimaginable even a decade ago. Our research has highlighted opportunities to maintain the overall health of people with HIV throughout their lifespans. We continue to expand the boundaries of scientific innovation in pursuit of durable technologies that could hasten an end to the HIV pandemic, especially preventive vaccines and curative therapy. During the COVID-19 public health emergency, our networks stepped forward to deliver swift results that advanced vaccines and therapeutics within a year of the World Health Organization declaring the global pandemic, while maintaining progress on our HIV research agenda. The impact of this collective scientific progress is evident worldwide.

Together with my NIH colleagues, I express sincere gratitude to the leaders and staff of current clinical trials networks, our research and civil society partners, and most importantly, clinical study participants and their loved ones, for their enduring commitment to supporting science that changes lives.

As we do every seven years, we are at a point in the funding cycle when our Institute engages research partners, community representatives, and other public health stakeholders in a multidisciplinary evaluation of network progress toward short- and long-term scientific goals. This process takes account of knowledge gained since the networks were last funded and identifies essential course corrections based on the latest scientific and public health evidence and priorities. Subsequent NIAID HIV research investments will build on the conclusions of these discussions.

Looking to the future, we envision an HIV research enterprise that follows a logical evolution in addressing new scientific priorities informed by previous research progress. We will fund our next networks to align with updated research goals to take us through the end of 2034. The HIV research community’s outstanding infrastructure is the model for biomedical research. Now, our capacity must reflect an increasing interdependence across clinical practice areas and public health contexts. Our goals for the next networks are to:

• Maintain our support for core discovery and translational research to address gaps in biomedical HIV prevention and treatment, including a vaccine and therapeutic remission or cure. Our objective is to identify effective interventions that expand user choice and access, as well as improve quality of life across the lifespan;
• Provide the multidisciplinary leadership required to address the intersections between HIV and other diseases and conditions throughout the lifespan, including noncommunicable diseases, such as diabetes mellitus and substance use disorder, and infectious diseases that share health determinants with HIV, such tuberculosis and hepatitis;
• Compress protocol development and approval timelines for small and early-stage trials to enable more timely translation of research concepts to active studies; 
• Respond to discrete implementation science research questions as defined by our implementation counterparts, including federal partners at the Centers for Disease Control and Prevention, Health Resources and Services Administration, U.S. Agency for International Development, agencies implementing the U.S. President’s Emergency Plan for AIDS Relief, and other nongovernmental funders and implementing organizations worldwide;  
• Draw from nimble and effective partnerships at all levels to leverage the necessary combination of financial resources, scientific expertise, and community leadership and operational capacity to perform clinical research that is accessible to and representative of the populations most affected by HIV, especially people and communities that have been underserved in the HIV response; 
• Leverage our partners’ platforms if called on to close critical evidence gaps for pandemic response; and,
• Plan for impact by mapping clear pathways to rapid regulatory decisions, scalable production, and fair pricing before the start of any efficacy study.

Our shared goal is to produce tools and evidence to facilitate meaningful reductions in HIV incidence, morbidity and mortality globally. I invite you to continue sharing your thoughts with us to help shape the future of HIV clinical research, and to review the blogs on specialized topics that we will continue to post on the HIV Clinical Research Enterprise page in the coming weeks. Please share your feedback, comments, and questions at NextNIAIDHIVNetworks@mail.nih.gov. Submissions will be accepted through December 2024. 

Fourteen vaginal bacterial species and the presence of a protein that promotes inflammation were associated with increased odds of HIV acquisition in a study of more than 500 cisgender women in African countries with high HIV incidence. The study was the largest to date to prospectively analyze the relationship between both the vaginal microbiome and vaginal tissue inflammation and the likelihood of acquiring HIV among cisgender women in this population. The NIAID-sponsored research was published in The Journal of Infectious Diseases.

Research is limited regarding the potential impacts of vaginal bacteria and inflammatory markers on HIV acquisition. Only one previous study has characterized both factors in women before they had HIV to investigate their odds of acquiring the virus, but the number of HIV acquisition events in that study was low, potentially limiting their ability to detect associations.

To increase understanding of these issues, researchers analyzed vaginal swab samples from 586 cisgender women participating a large biomedical HIV prevention clinical trial in South Africa, Uganda and Zimbabwe, and compared the bacterial and inflammatory profiles of samples from 150 participants who acquired HIV during the study with the samples of 436 participants who did not. The team identified 14 bacterial species associated with HIV acquisition and noted that participants whose samples contained most or all of those bacteria had the highest odds of acquiring HIV, while the presence of none or few of the identified bacteria was associated with the lowest odds of HIV acquisition. They similarly identified six inflammatory cytokines and chemokines—proteins that communicate with other cells to prompt the body to fight infections through inflammatory processes—associated with HIV acquisition, and identified the highest odds of HIV acquisition in participants whose samples contained all six of those proteins. Furthermore, they identified a single chemokine called interferon gamma-induced protein 10 associated with the highest odds of HIV acquisition out of the six.

These results suggest that strategies to reduce concentrations of the 14 identified bacterial species and inflammatory proteins could help prevent HIV acquisition, according to the authors. They also recommended that additional studies be conducted to understand the mechanisms by which these factors contribute to biological susceptibility to HIV.

Reference: Srinivasan, S et al. Vaginal Bacteria and Proinflammatory Host Immune Mediators as Biomarkers of HIV Acquisition 3 Risk among African Women. Journal of Infectious Diseases. DOI 10.1093/infdis/jiae406 (2024).

This blog is the second in a series about the future of NIAID's HIV clinical research enterprise. For more information, please visit the /research/hiv-research-enterprise page.

The impact of clinical research is often measured by its outcomes. From trials that provide groundbreaking evidence of efficacy to those stopped early for futility, the end results of clinical trials shape practice and future research priorities. However, years of effort from scientists, study teams and study participants while a trial is underway are sometimes overshadowed by final study outcomes. In this regard, trial implementation requires clinical research sites’ operational excellence for the duration of a study. Access to relevant populations depends on the location of each clinical research site as well as investigators' and clinical care providers’ engagement with the local community and understanding of their needs and preferences. A high-functioning clinical research site anchored in the communities it works in and comprised of cohesive, well-integrated components is essential to producing high-quality outputs. 

Currently, NIAID supports four research networks as part of its HIV clinical research enterprise. The networks are made up of more than 100 clinical research sites, each with local experts, robust research infrastructure, and well-trained, cross-functional staff who maintain standardized procedures and quality controls aligned with their network.

Every seven years, NIAID engages research partners, community representatives, and other public health stakeholders in a multidisciplinary evaluation of network progress toward short- and long-term scientific goals. This process takes account of knowledge gained since the networks were last funded and identifies essential course corrections based on the latest scientific and public health evidence. Subsequent NIAID HIV research investments build on the conclusions of these discussions. This process includes examining the networks’ infrastructure model, which the Institute updates and refines to stay aligned with its scientific priorities. 

The HIV clinical trials network sites have made tremendous contributions to NIH’s scientific priorities by offering direct access to and consultation with populations most affected by HIV globally, and by delivering high-quality clinical research with strong connections to trusted community outreach platforms. Their approach to community engagement anchors clinical research sites beyond the scope of any individual study, and when possible, aligns scientific questions and study protocols based on local context. 

Since the start of the 2020 research network grant cycle, HIV clinical research sites have enrolled about 93,000 participants across 78 clinical trials in 25 countries. The networks were able to quickly pivot to support NIAID’s emerging infectious disease priority areas, including COVID-19 and mpox. Of the 93,000 participants since 2020, approximately 78,000 were enrolled into COVID-19 clinical trials sponsored by NIAID’s Division of AIDS. 

Clinical trials sites currently operate with a hub-and-spoke model, with each hub providing centralized support to their linked clinical research sites. This model leverages shared resources where possible and practical, and ensures robust oversight to promote high-quality clinical trial operations. Hubs provide infrastructure and services including laboratory, pharmacy, regulatory, data management, and training to support execution of NIAID-sponsored clinical research. 

Future networks will need to maintain core strengths of current models while expanding capacity in areas vital to further scientific progress. These include operations that inform pandemic responses and extending our reach within communities impacted by HIV, including populations historically underrepresented in clinical research. Additionally, there may be opportunities for clinical research sites and other partners to conduct implementation science research based on their capacity and access to relevant populations in the context of specific scientific questions. 

Make seamless progress on established and emerging scientific priorities

Our goals include maintaining the strength and flexibility of our current network model and infrastructure to support established scientific priorities that improve the practice of medicine, including high-impact registrational trials to identify new biomedical interventions and support changes to product labelling. The networks also must remain capable of directing operations to generate evidence on interventions for pandemic responses. 

Engage underserved populations for more representative studies 

Building on its current reach, NIAID and its partners have identified opportunities to expand or strengthen our connections to medically underserved populations affected by HIV, and to increase representation of geographic areas with limited access to current clinical trials sites. We also are seeking clinical research sites with longstanding community relationships and experience conducting randomized clinical trials that include Black gay, bisexual, and other men who have sex with men, transgender people, people who sell sex, people who use drugs, and adolescent girls and young women, as well as populations in African countries with a high HIV prevalence. 

Integrate implementation science within clinical research practice

Implementation science is the scientific study of methods and strategies that facilitate the uptake of evidence-based practice and research into regular use by practitioners and policymakers. As biomedical HIV prevention, treatment, and diagnostic options expand, our scientific questions must expand to address not only whether an intervention works, but how it can be delivered to offer health care choices that people need, want and are able to use. This expanded scientific scope calls for research sites to have a diverse reach and skill sets, including experience and capacity for conducting implementation science research and fostering and maintaining partnerships with organizations that conduct implementation science research on key topics and interventions on which implementers seek stronger evidence.

The research community plays an essential role in shaping NIAID’s scientific direction and research enterprise operations. We want to hear from you. Please share your questions and comments at Next NIAID HIV Networks.

About NIAID’s HIV Clinical Trials Networks

The clinical trials networks are supported through grants from NIAID, with co-funding from and scientific partnerships with NIH’s National Institute of Mental Health, National Institute on Drug Abuse, National Institute on Aging, and other NIH institutes and centers. There are four networks—Advancing Clinical Therapeutics Globally for HIV/AIDS and Other Infections, the HIV Vaccine Trials Network, the HIV Prevention Trials Network, and the International Maternal Pediatric Adolescent AIDS Clinical Trials Network.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and joint destruction. As with many autoimmune diseases, RA disproportionally affects females. The development of RA is believed to involve complex interactions that include both environmental and genetic factors, and understanding the contributions of these factors continues to evolve. Many people with RA have detectable circulating autoantibodies—immune proteins that react to an individual’s own proteins—in their serum for years before experiencing any symptoms. The presence of these autoantibodies prior to joint inflammation suggests that the autoimmune process is initiated elsewhere in the body. 

Recent studies have pointed to an imbalance of commensal bacteria in mucosal sites as a possible cause of inflammation leading to the initiation of the autoimmune process. In particular, expansion of Prevotella copri in stool was associated with new-onset RA, and additional studies found that people living with RA were more likely to have immune reactivity against P. copri, making this an opportune candidate to further investigate. Given that several previous studies using samples from people with RA reported immune reactivity to a P. copri protein called Pc-p27, this study aimed to further characterize the development and timing of antibody responses to this protein in people at risk for or with RA. 

Researchers examined levels of immunoglobulin (Ig)G, an antibody associated with systemic immune responses, and IgA, an antibody associated with immune responses at mucosal sites, in individuals at risk for developing RA, those with early-onset RA, and those with established RA. Overall, people with RA had higher levels of both IgA and IgG anti-Pc-p27 antibodies than their matched healthy controls. When participants were stratified into early and established RA groups, there were notable differences in antibody level trends. Those in the early RA group had trending increases in IgG anti-Pc-p27 antibody levels, while participants with established RA had a significant elevation in IgA anti-Pc-p27 antibody levels. Furthermore, at-risk participants did not have higher IgA or IgG anti-Pc-p27 levels than their matched controls. In the 23 participants in the at-risk group who developed RA during the study, there was no significant increase in either IgA or IgG anti-Pc-p27 antibody levels between the visits before and after receiving their RA diagnosis.

Additional analysis was done to further interrogate the connection between the two known autoantibodies associated with the development of RA, anti-CCP and RF, and the observed differences in IgA and IgG anti-Pc-p27 antibody levels between the RA groups. All RA participants who were positive for both autoantibodies had significantly higher IgA and IgG anti-Pc-p27 antibody levels compared to matched healthy participants in the control group. In addition, at-risk participants who were anti-CCP positive but RF negative had higher IgG anti-Pc-p27 antibody levels than those in the control group.

Taken together, the findings of this study extend the conclusions of previous studies associating immune activity against P. copri with the development of RA. Additional work is needed to understand how P. copri and other microorganisms may contribute to disease pathogenesis, which may ultimately lead to the development of novel interventions to prevent disease in individuals at risk of developing RA. A thorough understanding of the underlying mechanisms that lead to increased susceptibility to autoimmune diseases in women is a critical step in prevention.

References:

Seifert, JA et al. Association of Antibodies to Prevotella copri in Anti–Cyclic Citrullinated Peptide-Positive Individuals At Risk of Developing Rheumatoid Arthritis and in Patients With Early or Established Rheumatoid Arthritis. Arthritis & Rheumatology. DOI 10.1002/art.42370