Oxford Begins First-in-Human Trial of Lassa Fever Vaccine Using COVID-19 Platform Technology
Key Insights
The Oxford Vaccine Group (search) has administered the first dose of its ChAdOx1 Lassa vaccine (search) to a volunteer in a groundbreaking first-in-human trial, marking a major milestone in combating the deadly virus.
The vaccine utilizes the same viral vector platform as the Oxford/AstraZeneca COVID-19 vaccine, which saved an estimated 6 million lives in its first year alone.
Up to 700 million people could live in regions at risk of Lassa fever (search) by 2070, yet no licensed vaccines or treatments currently exist for this WHO priority pathogen.
The Oxford Vaccine Group (search) has administered the first dose of its experimental Lassa fever (search) vaccine to a volunteer, launching a pivotal first-in-human clinical trial that could provide the first licensed protection against a deadly virus that threatens hundreds of millions of people across West Africa.
The trial, funded by the Coalition for Epidemic Preparedness Innovations (search) (CEPI) and conducted in Oxford, will evaluate the safety and immune response of the ChAdOx1 Lassa vaccine (search) in 31 participants aged 18-55. The vaccine leverages the same viral vector platform technology used in the Oxford/AstraZeneca COVID-19 vaccine, which is estimated to have saved 6 million lives in its first year alone.
Critical Public Health Need
Lassa fever (search), caused by the Lassa virus (search) and primarily transmitted through rodents, can result in severe complications including deafness, severe bleeding, and death. First discovered in Nigeria in the late 1960s, the disease is endemic throughout West Africa and has been identified by the World Health Organization as a priority pathogen requiring urgent research and development due to its significant epidemic potential.
The disease burden is projected to expand dramatically, with experts estimating that up to 700 million people could live in regions at risk of Lassa fever (search) by 2070. Despite this growing threat, no licensed vaccines or treatments currently exist for the disease.
"Vaccines are one of the most powerful tools we have in global health: they save lives, stop outbreaks, and strengthen health systems," said Professor Maheshi Ramasamy, Chief Investigator of the trial at the Oxford Vaccine Group (search). "Building on Oxford's world-leading experience in developing vaccines for emerging infections and pandemics, including COVID-19, this study is a crucial step toward protecting vulnerable communities from the devastating impact of Lassa fever (search)."
Proven Platform Technology
The vaccine was developed by researchers at the Pandemic Sciences Institute (search), University of Oxford, using the established ChAdOx1 viral vector platform. This technology has demonstrated both safety and efficacy through its successful deployment in the Oxford/AstraZeneca COVID-19 vaccine program.
CEPI supported both the early preclinical development and the current clinical trial. Dr. Katrin Ramsaeur, Lassa Disease Programme Lead at CEPI, described the trial launch as "a transformative milestone in the fight against the deadly Lassa fever (search)," noting that it represents the culmination of "years of rigorous and innovative science, steadfast collaboration, and an unwavering commitment to global health."
Regional Leadership and Future Plans
Beyond the Oxford trial, a second phase 1 study is scheduled to begin in Ghana early next year, reflecting the collaborative approach to addressing this regional health threat. The development pathway is being coordinated through the Lassa fever (search) Coalition, a consortium led by the West African Health Organization (search) (WAHO) with support from CEPI and other partners.
The coalition brings together West African leaders and public health experts working with vaccine manufacturers to accelerate development and ensure equitable introduction of Lassa fever (search) vaccines across affected regions.
"For more than half a century, Lassa fever (search) has affected lives in West Africa — from our families and livelihoods to our hospitals and economies," said Dr. Virgil Lokossou, Director of Healthcare Services at WAHO. "Oxford's vaccine candidate brings real promise for protection against this deadly disease and this clinical trial arrives at a moment when regional efforts to defeat Lassa fever are stronger than ever."
Trial Design and Next Steps
The current phase 1 trial, designated VITAL01, will primarily assess the vaccine's safety profile while also measuring immune responses in the study population. The 31-participant study represents the first step in what could be a multi-phase development program leading to regulatory approval and widespread deployment.
The Oxford Vaccine Group (search), which led the rapid clinical development of COVID-19 vaccines during the pandemic, brings three decades of experience in vaccine research spanning basic science through phase III clinical trials. The group has made significant contributions to global immunization policy and specializes in vaccines for outbreak pathogens and pandemic threats.