As syphilis rates continue to rise in the United States, emergency departments may be a way for people with limited healthcare access to get screening and treatment. A NIAID study derived an emergency department syphilis screening strategy to help people get diagnosed before their infection reaches an advanced stage. This approach could reduce disease burden and prevent cases of congenital syphilis, in which the bacteria are passed from a birth parent to their infant. The findings were published today in Open Forum Infectious Diseases. 

Syphilis, caused by the bacteria Treponema pallidum, is a common sexually transmitted infection (STI). Untreated syphilis can cause nervous system and organ damage, as well as pregnancy complications for birth parents and their infants. In the United States, adult and congenital syphilis cases have increased by 78.9% since 2018, with a drastic 17% increase in 2022 alone. The syphilis surge has disproportionately burdened historically and medically underserved populations. These health disparities underscore the need for greater access to syphilis testing and treatment resources. 

Researchers analyzed blood samples retrospectively from 1,951 adults who presented to a Baltimore emergency department over the course of a month in early 2022. They found 103 people (5.3%) had detectable treponemal antibodies to syphilis, which are indicative of a previous or active syphilis infection. Of them, 23 people (22%, 1.1% overall) had high non-treponemal antibody levels, which indicate active syphilis. The study investigators prioritized identifying people with active syphilis and performed statistical analyses to determine the associated risk factors to inform a potential screening strategy.  

The proportion of samples with active syphilis was highest among people with HIV and people without a primary care provider. Among women with active syphilis, eight out of nine (88%) were between the ages of 18 and 49 years, which is defined as the window of reproductive age. Statistical analyses demonstrated that screening people living with HIV, without a primary care physician, and women aged 18 to 49 years would have identified 21 of the 23 people (91%) with active syphilis in the participating emergency department.

Typically, emergency departments only screen people for syphilis if they present with symptoms consistent with primary or secondary syphilis. According to the authors, the findings demonstrate the advantages of conducting focused syphilis screening during routine emergency department visits, particularly for communities who may have limited access to health care. They suggest that implementing a screening strategy informed by this study could help address the underdiagnosis of syphilis while expanding the reach of effective prevention and treatment, reducing the burden of adult and congenital syphilis. Finally, the continued syndemic of HIV and syphilis—two epidemics that interact with each other, with adverse effects on the health of communities—highlights the opportunity to provide comprehensive HIV and STI prevention and care in the emergency department, where people with high incidence frequently seek care. 

Reference: 

J Hunt, et al. A Potential Screening Strategy to Identify Probable Syphilis Infections in the Urban Emergency Department Setting. Open Forum Infectious Diseases. DOI: https://doi.org/10.1093/ofid/ofae207 (2024).

An HIV vaccine candidate elicited trace levels of HIV broadly neutralizing antibodies (bNAbs) and high levels of other key immune cells in an early-stage clinical trial. This immune response is an important signal that, if antibody levels can be further amplified, the vaccination strategy might be able to prevent HIV. The findings of this NIAID-supported trial were published in the journal Cell.

HIV has genetic diversity that makes it difficult to target with a vaccine, but bNAbs are thought to be key to overcoming that hurdle because they bind to parts of the virus that remain relatively stable even when it mutates. Several classes of HIV-specific bNAbs have been identified, and each class binds to a different stable section of the virus’ surface. Some people with HIV generate bNAbs naturally through a process that typically occurs over years. For a preventive vaccine, researchers seek to accelerate the process by which the immune system generates bNAbs and to do so in people who do not have HIV. 

The clinical trial examined the ability of a vaccine concept to elicit bNAbs that bind to the membrane proximal external region (MPER) of an HIV surface protein. The study enrolled 24 participants, of whom 20 were randomly selected to receive vaccine doses. The remaining four participants received placebo injections. Fifteen participants in the vaccine arm received two doses, and five participants received three doses. The team then analyzed study participant blood samples. 

They found that 13 vaccine recipients generated early-stage MPER-directed antibodies after two doses. Among the five participants who received three doses, the antibodies in samples from two of them could neutralize many common globally circulating HIV strains in vitro, i.e., in a test tube or culture dish. One of those two participants had B cells—immune cells that produce antibodies—showing signs of maturing in such a way that they would be able to produce MPER-directed bNAbs if stimulated further. The other participant had started producing MPER-directed bNAbs. Vaccine recipients also had evidence of CD4+ T cell activity, which is a crucial step in enabling antibody development. One vaccine recipient experienced anaphylaxis, a known but rare allergy-related adverse event, which was promptly managed and resolved. The team investigated the cause of the event, which was likely from an additive used to help stabilize the vaccine contents. The trial was halted at that time.  

The research was sponsored by NIAID, co-funded by the Bill & Melinda Gates Foundation, and conducted by the Duke Consortium for HIV/AIDS Vaccine Development (CHAVD), one of two NIAID-supported HIV vaccine consortia, in collaboration with the NIAID-funded HIV Vaccine Trials Network. This study provided the proof of concept that a vaccine can induce bNAbs in people, which is a key question being pursued in the HIV vaccine research field. Moreover, bNAbs were detected within weeks, which is much faster than the antibody response in people with HIV. According to the authors, it is likely that an effective vaccine will need to build on and amplify the immune response that was observed in this study. Together, the clinical trial results identified ways that the vaccine’s safety and efficacy must be enhanced before it advances through further evaluation, and a new vaccine candidate is being developed based on these findings.

NIAID is grateful to the research teams and volunteers who participate in HIV vaccine studies. 

For more information about this study, please visit ClinicalTrials.gov and use the study identifier NCT03934541.

Reference 

W Williams et al. Vaccine induction of heterologous HIV-1-neutralizing antibody B cell lineages in humans. Cell DOI: 10.1016/j.cell.2024.04.033 (2024)

A preventive vaccine for gonorrhea would be a major advance in public health, according to an editorial co-authored by NIAID Director Jeanne Marrazzo, M.D., M.P.H, and Myron Cohen, M.D., director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill. The editorial, published in the Journal of Infectious Diseases, provides context on new mathematical modeling projecting the cost-effectiveness of the meningitis B vaccine 4CMenB, which is currently being evaluated as a preventive intervention for gonorrhea. 

Gonorrhea, a common sexually transmitted infection, afflicts more than 80 million adults each year, according to the World Health Organization. It is caused by the Neisseria gonorrhoea bacterium. Untreated gonorrhea can lead to serious and permanent health conditions, such as pelvic inflammatory disease, painful swelling and blockages in male reproductive organs, and infertility. While usually treatable with antibiotics, N. gonorrhoeae bacteria have demonstrated resistance to most existing classes of antibiotics. The genetic sequences of N. gonorrhoeae and Neisseria meningitidis group B, the bacteria that can cause meningitis B, are closely related, which have led researchers to explore whether the 4CMenB vaccine, approved by the Food and Drug Administration for meningitis B, might also prevent gonorrhea. 

NIAID is sponsoring an efficacy study of the 4CMenB vaccine for gonorrhea prevention in more than 2,000 people aged 18-50 years in Malawi, Thailand, and the United States. The Kirby Institute is studying the same vaccine among gay, bisexual, and other men who have sex with men in Australia, and GlaxoSmithKline is studying a vaccine specifically designed to prevent gonorrhea, to assess its safety and potential efficacy. All studies are expected to report results within the next two years. 

The mathematical modeling published with the editorial was led by Imperial College London with funding through the Global Health EDCTP3 Joint Undertaking and the UK Health Security Agency. The model projected how the dosing, vaccine effectiveness, health promotion, and availability for those most likely to benefit could affect the cost effectiveness of 4CMenB vaccination for gonorrhea, showing a potential benefit even if efficacy is low in forthcoming study results. Models will be able to generate a more accurate cost-effectiveness estimate once efficacy studies are complete.

References

MS Cohen et al. What if We Had a Vaccine that Prevents Neisseria gonorrhoeae? Journal of Infectious Diseases DOI: 10.1093/infdis/jiae160 (2024)

D Nikitin et al. Cost-effectiveness of 4CMenB Vaccination Against Gonorrhea: Importance of Dosing Schedule, Vaccine Sentiment, Targeting Strategy, and Duration of Protection. Journal of Infectious Diseases DOI: 10.1093/infdis/jiae123 (2024)

by Jeanne Marrazzo, M.D., M.P.H., NIAID Director

The HIV research community is led by scientists with deep personal commitments to improving the lives of people with and affected by HIV. Some researchers, like me, have pursued this cause since the start of the HIV pandemic, growing our careers studying HIV from basic to implementation science. Our collective decades of work have generated HIV testing, prevention and treatment options beyond what we could have imagined in the 1980s. Those advances enable NIAID to explore new frontiers: expanding HIV prevention and treatment modalities, increasing understanding of the interplay between HIV and other infectious and non-communicable diseases, optimizing choice and convenience, and building on the ever-growing knowledge base that we need to develop a preventive vaccine and cure. The next generation of leaders will bring these concepts to fruition, and we need to welcome and support them into the complex and competitive field of HIV science.

Click below for a video in which NIAID grantees and I discuss the value and experience of early-stage HIV investigators (the audio described version is here):

NIAID wants to fund more new HIV scientists and we have special programs and funding approaches to meet that goal. This week, the NIH Office of AIDS Research will host a virtual workshop on early-career HIV investigators tomorrow, April 24, and NIAID will host its next grant writing Webinars in May, June, and July.

For more information about programs and support for new and early-stage investigators as well as people starting to implement their first independent grant, visit these NIAID and NIH resources: 

Information for New Investigators (NIAID)

HIV/AIDS Information for Researchers (NIAID)

OAR Early Career Investigator Resources (NIH)

Resources of Interest to Early-Stage Investigators (NIH)

Early Career Reviewer Program (NIH)

Sexually transmitted infections (STIs) are caused by bacteria, viruses, or parasites. STIs have a devastating impact on adults and infants and annually affect millions of people in the United States. Certain STIs can increase a person’s risk of developing cancer and increase the likelihood of acquiring or transmitting HIV. In addition, STIs can cause long-term health complications, especially in the reproductive and central nervous systems. In rare cases, they can lead to serious illness or death. 

NIAID supports research across the spectrum from basic to clinical science to develop effective diagnostic, preventive and therapeutic approaches to STIs in alignment with the National STI Strategic Plan. In recognition of National STI Awareness Week, NIAID shares a snapshot of new projects and recent scientific advances in STI research. 

Improving treatment for syphilis and trichomoniasis

New reports of syphilis and congenital syphilis are increasing at an alarming rate in the United States. Syphilis is caused by the bacterium Treponema pallidum. Benzathine penicillin G (BPG) is one of only a few antibiotics known to effectively treat syphilis. There is currently a shortage of BPG, and some people are allergic to penicillin antibiotics. In February 2024, NIAID convened a workshop with a wide range of experts on alternative therapies to BPG for the treatment of adult syphilis, neurosyphilis, and syphilis in pregnant persons and infants. The workshop addressed preclinical evaluation of candidate drugs, the potential need for studies on how candidate drugs are processed in the body during pregnancy, and how to approach clinical trials of treatment for congenital syphilis. This work is part of NIAID’s comprehensive portfolio of syphilis diagnosis, prevention, and treatment research. 

Trichomoniasis is the most common parasitic STI, caused by Trichomonas vaginalis. Trichomoniasis can increase the risk of getting or spreading other STIs, including HIV. The parasite can also cause inflammation of the cervix and the urethra. T. vaginalis is treated with an antibiotic drug class called nitroimidazoles. The currently recommended nitroimidazole, called metronidazole, cures 84-98% of T. vaginalis cases but does have high rates of breakthrough infection. A new project led by Tulane University will examine a single dose of secnidazole, a medicine in the same drug class, as a more effective and cost-effective treatment option for women and men. 

Developing a vaccine for herpes simplex virus 2

Herpes simplex virus 2 (HSV-2) is a common subtype of herpes simplex virus that is transmitted through sexual contact. The Centers for Disease Control and Prevention estimates that 18.6 million people aged 15 years and older United States live with HSV-2. In severe cases, HSV-2 may lead to life-threatening or long-term complications. There is no licensed preventive HSV-2 vaccine, and there is no cure. A new project led by the University of Pennsylvania seeks to define correlates of protection for HSV-2, meaning they intend to identify immune processes involved in preventing HSV-2 disease. They will do this by analyzing laboratory samples from animal studies of a promising preventive vaccine candidate that they developed with prior funding. That vaccine candidate is also now in an industry-sponsored early-stage clinical trial. The same project will expand on the HSV-2 targets in the preventive vaccine to develop a therapeutic vaccine concept to reduce recurrent outbreaks. This research responds to the scientific priorities in the NIH Strategic Plan for Herpes Simplex Virus Research.

Increasing fundamental knowledge of bacterial vaginosis 

Bacterial vaginosis (BV) results from an imbalance in the vaginal microbiome. BV can be caused by sexual activity, douches and menstrual products. BV can increase women’s biological susceptibility to HIV and other STIs and can cause premature birth or low birthweight if untreated in pregnant people. In a recent publication, NIAID-supported researchers, led by researchers at the University of Washington and University of California San Diego, shared findings on how damage to the vaginal skin barrier occurs during bacterial vaginosis. Those skin barrier cells, called epithelial cells, are covered in carbohydrate molecules called glycans. The research team found that people with BV had damaged glycans on their vaginal epithelial cells. They suggested that future work should examine the relationship between treatment and restoration of normal glycans. If an association is detected, it could help healthcare providers monitor for successful treatment outcomes to reduce the likelihood that BV will return after a course of treatment. The findings were published in Science Translational Medicine. 

These activities are among the research investments in NIAID’s STI portfolio. For more information on STIs, please visit:

• NIAID Diseases & Conditions: Sexually Transmitted Infections
• U.S. Department of Health and Human Services STI National Strategic Plan

The National Institutes of Health recently issued $26M in awards to HIV research institutions in its fifth year supporting implementation science under the Ending the HIV Epidemic in the U.S. (EHE) initiative. These awards are the latest investments in a program that is rapidly and rigorously generating evidence to inform the unified domestic HIV response by agencies in the Department of Health and Human Services. 

The EHE initiative aims to achieve a 90% reduction in the number of new HIV infections in the United States by 2030. Since the initiative was announced in 2019, NIH has contributed by supporting implementation science projects through its network of Centers for AIDS Research (CFAR) and the National Institute of Mental Health (NIMH) AIDS Research Centers (ARC). CFARs are co-funded by 11 NIH institutes and centers (ICs), including the National Institute of Allergy and Infectious Diseases (NIAID). NIH ICs provide scientific stewardship to participating institutions in collaboration with the Fogarty International Center and the NIH Office of AIDS Research, which coordinates the NIH HIV research program across the agency. CFAR and ARC-affiliated investigators conduct research in jurisdictions that are disproportionately affected by HIV, and many of the CFAR and ARC member institutions are based in these communities. 

VIDEO: Jeanne Marrazzo, M.D., M.P.H., NIAID Director, discusses NIH’s role in the EHE (audio description version here):

NIH EHE projects enable academic institutions to partner with state and local leaders to jointly translate implementation research findings into improved delivery of HIV testing, prevention, treatment, and response services for priority populations and in priority geographic areas. Projects funded this year are designed to increase and share available knowledge on locally appropriate strategies to: 

• detect and respond to HIV “clusters,” i.e., groups of people and communities experiencing rapid HIV transmission;
• leverage pharmacies as HIV service locations; 
• ensure uninterrupted HIV care for people returning to their communities following incarceration; and
• develop approaches that address intersecting diseases and conditions that exacerbate health inequities and impact HIV outcomes, including such as viral hepatitis, sexually transmitted infections, and substance use and mental health disorders.

Since Fiscal Year 2019, NIH has funded 253 projects across 50 geographic areas prioritized by EHE. The latest EHE awards to CFARs and ARCs support 47 projects, 8 implementation science hubs, and 1 coordinating center. Hubs provide technical support, coaching, training, and consultative services to funded EHE research teams. The coordinating center provides infrastructure for collaboration and sharing best practices in HIV implementation science. In addition to the CFAR/ARC supplements, NIH supported multiple larger research projects in 2023, including 3 R01 awards, 2 R34 awards, and 1 coordinating center. In September 2023, NIH released a Notice of Special Interest to solicit project proposals from independent investigators for Fiscal Year 2024.

EHE Project Spotlights

The knowledge generated by NIH EHE projects is reviewed with HHS EHE partners to accelerate learning and program improvement. Two projects below illustrate how EHE implementation science projects have already enhanced locally tailored HIV service delivery:

Miami, Florida

Miami-Dade County, Florida has one of the highest rates of HIV incidence in the United States, and yet use of pre-exposure prophylaxis (PrEP) to prevent HIV acquisition remains relatively low. Researchers at the University of Miami, in collaboration with the Florida Department of Health (DOH) and a local community-based organization called Prevention305, developed a process to apply real-time DOH epidemiologic data to prioritize new geographic locations for placement of their mobile PrEP clinics. In collaboration with community partners, the project developed a new outreach approach: “Test-to-PrEP,” in which people using PrEP are engaged to distribute free HIV self-tests and PrEP referrals through their social networks. They have worked with 100 current PrEP clients to engage members of their social network with information about PrEP provide them with HIV self-tests. More than one third of the 117 HIV self-test kit recipients who confirmed they used the test reported they had not previously known about PrEP. Self-reported knowledge and likelihood to use PrEP increased significantly after kit receipt. PrEP clients also reported feeling comfortable with the distribution and enthusiastic about the strategy. Their work has provided a blueprint for mobile HIV prevention and related services as a strategy to interrupt further transmission.

Mobile clinic service team in the Liberty City neighborhood of Miami, Florida

Credit: University of Miami

Shelby County, Tennessee

Rural areas like Shelby County pose distinct challenges to HIV service delivery, including a lack of outpatient providers and fragmented health care and social services, as well as stigma and medical mistrust. To overcome these barriers, researchers from University of Massachusetts, Lowell, in collaboration with the University of Memphis and the Shelby County Health Department, used an implementation research approach to adapt and provide an evidence-based training and capacity-building program in HIV care for existing community health workers (CHWs), with input from HIV care providers, people with HIV, and CHWs. CHWs are frontline public health workers who are also members of the community they serve. The team has trained 67 CHW to support HIV care across eight agencies and has provided coaching sessions to supervisors around how to sustain this workforce. They are assessing the sustainability and effectiveness of this program in addressing service gaps and improving health outcomes through follow-up surveys with health care agency staff and county health leaders. 

Community health worker Michelle Anderson discussing culturally relevant care HIV care with colleagues in Memphis, Tennessee.

Credit: University of Massachusetts, Lowell

In addition to NIH, HHS agencies and offices participating in EHE include the Centers for Disease Control and Prevention; the Health Resources and Services Administration; the Indian Health Service; the Office of the Assistant Secretary for Health; and the Substance Abuse and Mental Health Services Administration. 

To view a complete list of NIH research projects supported with EHE initiative funding, please visit the awards page. 

To learn more about EHE, please visit HIV.gov.

Reference: 

Butts, SA et al. Addressing disparities in Pre-exposure Prophylaxis (PrEP) access: implementing a community-centered mobile PrEP program in South Florida. BMC Health Services Research. DOI 10.1186/s12913-023-10277-1 (2023).

Johnson, AL et al. “Test-To-PrEP”: Assessing Reach and Adoption of a New Approach to Increase HIV Testing and PrEP Knowledge Using HIV Self-Test Kit Distribution Through PrEP Clients' Social Networks. Journal of Acquired Immune Deficiency Syndromes. DOI 10.1097/QAI.0000000000003294 (2023). 

Rajabiun, S et al. Using Implementation Science to Promote Integration and Sustainability of Community Health Workers in the HIV Workforce. Journal of Acquired Immune Deficiency Syndromes. DOI 10.1097/QAI.0000000000002966 (2023).