The first volunteer has received a dose of Oxford University’s experimental Lassa fever vaccine, marking a major advancement in global efforts to combat the deadly virus. The milestone was announced on Thursday by the Coalition for Epidemic Preparedness Innovations (CEPI) on its website.
The first-in-human trial, conducted by the Oxford Vaccine Group (OVG) and funded by CEPI, will evaluate the safety and immune response of the ChAdOx1 Lassa vaccine. A total of 31 healthy adults aged 18 to 55 will participate in the phase 1 study in Oxford, with a second trial scheduled to begin in Ghana early next year.
Lassa fever, first discovered in Nigeria in the late 1960s, is endemic in West Africa and spread primarily through contact with infected rodents. The virus can cause severe illness, including hemorrhage, hearing loss, and death. The World Health Organisation lists Lassa fever among priority pathogens requiring urgent research due to their potential for large outbreaks. Nigeria has recorded 995 confirmed cases and 184 deaths so far in 2025.
CEPI noted that the vaccine was developed using the same viral vector platform as the Oxford/AstraZeneca COVID-19 vaccine, credited with saving an estimated six million lives in its first year.
Chief Investigator for the trial, Prof. Maheshi Ramasamy, said launching the VITAL01 study represented a crucial step toward protecting vulnerable communities. “Vaccines are one of the most powerful tools we have in global health… this study is a crucial step toward protecting vulnerable communities from the devastating impact of Lassa fever,” she stated.
CEPI, which also supported the vaccine’s preclinical development, described the trial launch as transformative. Dr. Katrin Ramsauer, Lassa Disease Programme Lead at CEPI, said the development was made possible by years of scientific collaboration and commitment to global health. “While there is still important work ahead, this moment brings us closer to a future where communities no longer live in fear of this devastating disease,” she said.
READ ALSO: NCDC Flags Rising Lassa Fever Cases, Urges States to Step Up Year-Round Action
Broader efforts to accelerate vaccine availability are being coordinated by the Lassa Fever Coalition, led by the West African Health Organisation (WAHO) with support from CEPI and regional partners. The coalition aims to drive the vaccine toward licensure and ensure equitable access across affected countries.
WAHO’s Director of Healthcare Services, Dr. Virgil Lokossou, welcomed the development, noting the long-standing burden of Lassa fever on West African communities. “Our region is taking bold steps to change that story… Oxford’s vaccine candidate brings real promise for protection against this deadly disease,” he said.
The OVG, part of the University of Oxford’s Department of Paediatrics, also led rapid global vaccine development during the COVID-19 pandemic and continues to play a central role in research on emerging infectious diseases.