The global fight against Lassa fever has taken a major step forward as the Oxford Vaccine Group administered the first dose of a new Lassa fever vaccine to a volunteer in the United Kingdom.
The milestone, announced online on Thursday, took place in Oxford at the Oxford Vaccine Group, a unit of the University of Oxford’s Department of Paediatrics. It marks the start of a first-in-human clinical trial of the ChAdOx1 Lassa vaccine, funded by the Coalition for Epidemic Preparedness Innovations (CEPI).
Thirty-one healthy adults aged 18 to 55 will participate in the trial in Oxford, while a second phase-1 trial is expected to begin in Ghana in early 2026.
Prof. Ramasamy Maheshi, Chief Investigator of the trial at Oxford, described the study as a “crucial step toward protecting vulnerable communities. Vaccines are one of the most powerful tools we have in global health: they save lives, stop outbreaks, and strengthen health systems.”
She noted that the vaccine was developed using the same platform as the Oxford/AstraZeneca COVID-19 vaccine, which is estimated to have saved six million lives in its first year alone. “CEPI had earlier supported the preclinical development of the Lassa vaccine,” Maheshi added.
Dr. Katrin Ramsauer, CEPI’s Lassa Disease Programme Lead, called the launch a “transformative milestone,” highlighting years of scientific innovation and global collaboration. She said regional efforts are underway to accelerate vaccine licensure and ensure equitable access.
“The Lassa Fever Coalition, led by the West African Health Organization (WAHO) with support from CEPI and partners, is coordinating steps toward eventual rollout across affected countries,” Ramsauer said.
Dr. Virgil Lokossou, Director of Healthcare Services at WAHO, noted that Lassa fever has affected West African lives for more than half a century, impacting families, livelihoods, hospitals, and economies. “Our region is now taking bold steps to change that story,” he said.
Public health authorities in Nigeria, including the Nigeria Centre for Disease Control and Prevention (NCDC), continue to record seasonal outbreaks, with healthcare workers among those at risk.
If successful, the Oxford vaccine could become one of the first licensed preventive vaccines against Lassa fever, potentially reducing illness, deaths, and socioeconomic disruptions in West Africa.
Lassa fever, first discovered in Nigeria in the late 1960s, remains endemic across West Africa and continues to cause recurring outbreaks with high morbidity and mortality. The virus, primarily spread by rodents, can lead to severe complications including deafness, bleeding, and death.
