A recent report published on the Vaccine, a peer-reviewed medical journal, presents key priorities identified by experts from Europe, Africa, and the USA for advancing human Rift Valley Fever (RVF) vaccine research. The priorities include improving epidemiological data and modeling, enhancing diagnostic tools, defining vaccine use cases and regulatory pathways, and ensuring effective community engagement in vaccine deployment.

These priorities were discussed at a workshop held from June 4–5, 2024, in Nairobi, Kenya, organized by the Coalition for Epidemic Preparedness Innovations (CEPI). The meeting brought together 55 experts in public health, epidemiology, veterinary science, and vaccine research to discuss RVF epidemiology, modeling, and human vaccine development.

The experts collectively emphasized the importance of "multidisciplinary approaches for surveillance, prevention, detection, and control." They also underscored that RVF is a true One Health disease, necessitating collaborative efforts across sectors. While significant progress has been made in understanding the virus, the report highlights that RVF continues “to pose a risk for outbreaks, particularly in the face of the changing global climate.”

Ifakara scientist co-authors report
Among the contributors to the report is Dr. Grace Mwangoka, a scientist from Ifakara Health Institute. Dr. Mwangoka leads the clinical development of "DDVax," a human RVF vaccine candidate project funded by CEPI and implemented by Ifakara. The project, running from 2023 to 2027, aims to demonstrate that DDVax can safely provide high levels of immunogenicity and probable protection against RVF in endemic regions. 

Learn more about the project here.

Priorities for advancing RVF vaccine research
The two-day workshop identified five key priorities for advancing human RVF vaccine research. First, experts emphasized the need to look beyond outbreaks by gaining a deeper understanding of RVF's complex epidemiology to guide study design and vaccine use. They also highlighted the importance of improving data and models for better research, prediction, and intervention planning. 

The third priority focused on enhancing diagnostics, with experts calling for standardized and validated diagnostic tests and serological assays to inform epidemiology and case definitions. Another key area was defining the vaccine’s use, including determining the appropriate use case, regulatory pathway, implementation strategy, and considerations for equitable access to ensure optimal vaccine rollout. 

Lastly, experts stressed the importance of adopting people-centered approaches by engaging communities and social scientists to assess and ensure the acceptability of RVF vaccines.

Addressing gaps in RVF epidemiology
The workshop also identified gaps in RVF epidemiological data, particularly regarding virus transmission and persistence outside outbreak periods. Experts emphasized the need for an improved understanding of interepidemic virus transmission, enhanced genomic epidemiology to monitor virus evolution, and a standardized approach to serological assays to assess disease prevalence and immunity levels.

“Addressing epidemiological gaps through data collection, analysis, and modeling will benefit clinical trial planning for human RVF vaccines,” the experts noted. They further emphasized that findings from epidemiology and modeling studies could inform clinical trial design and guide resource prioritization to ensure optimal and equitable deployment of interventions once available.

The experts also highlighted the value of knowledge exchange and collaboration, noting that continued efforts as facilitated in the workshop, would benefit global efforts for RVF prevention and control.

This report, compiled by 55 experts, emphasizes that RVF is a One Health disease, requiring multidisciplinary and collaborative efforts across sectors. The insights from this workshop provide a roadmap for future RVF vaccine research and policy development, with a strong focus on equitable access and community engagement.

Read the publication here.

About Rift Valley fever
Rift Valley fever (RVF) is a zoonotic viral disease that primarily affects animals but can also infect humans. Infection can cause severe disease in both animals and humans. The disease results in significant economic losses due to death and abortion among RVF-infected livestock.

RVF virus is a member of the Phlebovirus genus. The virus was first identified in 1931 during an investigation into an epidemic among sheep in the Rift Valley of Kenya. Since then, outbreaks have been reported in sub-Saharan Africa. 
Currently, there are no RVF vaccines licensed for humans, but several candidates show promise in early-stage development.

Learn more about RVF here.