International AIDS Vaccine Initiative (IAVI) announced the Biomedical Advanced Research and Development Authority (BARDA), part of the Administration for Strategic Preparedness and Response within the U.S. Department of Health and Human Services, funded additional development and testing of IAVI’s single-dose vaccine candidates against the filoviruses Marburg virus (MARV) and Sudan ebolavirus (SUDV).

BARDA’s US$30 million award to IAVI expands the agency’s existing support of IAVI’s SUDV vaccine candidate and is in addition to a 2022 option under the initial award of $17 million to advance IAVI’s MARV vaccine candidate into clinical trials.

Filoviruses can cause severe hemorrhagic fever outbreaks and continue to impact the health security and geopolitical stability of Central and Western Africa.

“Ongoing intermittent viral hemorrhagic fever outbreaks, including the recent SUDV and current MARV outbreaks, demonstrate the importance of developing and stockpiling vaccines against known threats so they are ready for rapid evaluation in clinical trials,” said Swati Gupta, vice president and head of emerging infectious diseases and epidemiology at IAVI.

Gupta added: “The funding from BARDA will enable us to continue critical development and testing of IAVI’s filovirus vaccine candidates to facilitate better preparedness. It is essential that we efficiently accelerate our vaccine development efforts for known infectious disease threats now and apply our lessons learned from the past, such that we are truly better prepared when outbreaks continue to occur in the future.”

IAVI’s filovirus vaccine candidates are based on the same recombinant vesicular stomatitis virus (rVSV) vector used in ERVEBO, Merck’s highly efficacious Ebola Zaire (ZEBOV) vaccine, registered for use in several African countries. Vaccines and other medical countermeasures against SUDV and MARV remain key unmet needs because immunity against ZEBOV, SUDV, and MARV is not cross-protective.[1] IAVI’s SUDV and MARV candidates are referred to as rVSVΔG-SUDV-GP and rVSVΔG-MARV-GP, respectively.

With BARDA support, IAVI and its partners are advancing the rVSVΔG-SUDV-GP candidate through preclinical testing and plan to conduct a Phase I clinical trial in the United States in 2023.

In addition, IAVI and its partners are advancing an rVSVΔG-MARV-GP candidate following recently published preclinical data demonstrating that a single dose of the vaccine candidate is 100% efficacious at preventing Marburg virus disease in nonhuman primates.[2]The BARDA award also supports clinical development for rVSVΔG-MARV-GP.

MARV is associated with sporadic outbreaks in Africa and has been marked by an expanded regional footprint and increased outbreak frequency in recent years. Equatorial Guinea confirmed its first MARV outbreak this year, while Ghana and Guinea both confirmed their first outbreaks in 2022 and 2021, respectively. MARV disease has a case fatality rate of up to 88%.

In response to Uganda’s SUDV outbreak late last year, the World Health Organization (WHO) vaccine prioritization working group assembled to rapidly evaluate the suitability of three candidate Ebola vaccines for inclusion in a planned ring vaccination trial in Uganda. The group ranked IAVI’s rVSVΔG-SUDV-GP candidate the highest based on the proven safety and efficacy of ERVEBO.[4]

IAVI has convened expert collaborators for its filovirus vaccine development, including an innovative manufacturing partner, Batavia Biosciences, based in Leiden, Netherlands; members of the Viral Hemorrhagic Fever Consortium with its decades of experience researching Lassa, Marburg, and Ebola viruses; and preclinical investigators working on cutting-edge immunological assays.

This project is funded in whole or in part with federal funds from the Department of Health and Human Services; Administration for Strategic Preparedness and Response; Biomedical Advanced Research and Development Authority under contract number 75A50121C00077. Nonclinical development of rVSVΔG-MARV-GP is funded by the Defense Threat Reduction Agency of the U.S. Department of Defense (DOD).