The first volunteer has been dosed in a first-in-human trial of the Lassa vaccine, marking an unprecedented step towards treating Lassa fever. 

The vaccine, developed by the University of Oxford, is being assessed for its safety and the immune response it triggers in volunteers. Thirty-one people aged 18-55 will be trialled in total. 

Lassa fever is caused by the Lassa virus, which is primarily spread by rodents and can result in serious illnesses including deafness, severe bleeding and even death. First discovered in the late 1960s in Nigeria, Lassa fever is endemic in West Africa.  

The World Health Organization (WHO) has identified Lassa fever and related viruses as priority pathogens in urgent need of research and development because they pose a significant public health risk due to their potential to cause large outbreaks. Experts estimate that up to 700 million people could live in regions at risk of Lassa fever by 2070, although there are currently no licensed vaccines or treatments for Lassa fever. 

The Lassa vaccine, developed by the Pandemic Sciences Institute at the University of Oxford, is made using the same viral vector platform as the Oxford/AstraZeneca Covid-19 vaccine. 

“Vaccines are one of the most powerful tools we have in global health: they save lives, stop outbreaks, and strengthen health systems, and so we’re delighted to start the VITAL01 Lassa fever vaccine study here in Oxford,” said Professor Maheshi Ramasamy, Chief Investigator on the trial. 

“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.” 

Trials and licensure plans represent ‘bold steps’ to combat Lassa fever

Dr Katrin Ramsaeur, Lassa Disease Programme Lead at the Coalition for Epidemic Preparedness Innovations (CEPI), called the vaccine a ‘transformative milestone’ in tackling Lassa fever.  

“The launch of this Lassa vaccine clinical study has been made possible by years of rigorous and innovative science, steadfast collaboration, and an unwavering commitment to global health,” he said. 

“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.” 

As well as the launch of new clinical trials, plans to advance a Lassa vaccine to licensure are progressing through regional leadership and coordination by the Lassa fever Coalition. The consortium, led by the West African Health Organization (WAHO) with support from CEPI and partners, is made up of West African leaders and public health experts working with vaccine makers to accelerate the development and future equitable introduction of Lassa fever vaccines across the affected region. 

“For more than half a century, Lassa fever 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. 

“Now, our region is taking bold steps to change that story. By working together with partners like the University of Oxford through the Lassa fever Coalition, we are leading the way in confronting this epidemic threat so that it no longer undermines our health and societies.  

“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.” 

Bruno Quinney, Content Team, DDW