An international consortium of researchers specialising in human challenge studies is embarking on a US$57 million project to develop advanced, virus-blocking coronavirus vaccines that could stop SARS-CoV-2 and other coronaviruses from infecting people.
Led by Imperial College London and co-funded by the European Union’s Horizon Europe Programme and CEPI, the Coalition for Epidemic Preparedness Innovations, the consortium of more than a dozen scientific teams and organisations will begin by running trials to select particular viruses and identify the best conditions under which to safely induce infection in healthy volunteers. A human challenge study is a carefully managed medical research study, during which volunteers are intentionally given an infection in a safe way, with healthcare support.
Researchers at multiple clinical research facilities will then use a selected virus to try to infect healthy volunteers who have received an experimental vaccine. Unlike traditional vaccines which are injected into muscle, these experimental vaccines will be inhaled into the lungs or sprayed in the nose and are designed to induce a type of protection known as mucosal immunity – which scientists believe could be the key to stopping onward transmission of coronaviruses.
“Vaccines that can stop transmission of a virus, rather than only reducing the severity of the disease it causes, are crucial to being able to end pandemics and epidemics swiftly,” said Dr Richard Hatchett, CEPI’s Chief Executive Officer. “If we could find a way to induce virus-blocking mucosal immunity with the next generation of COVID-19 vaccines, for example, we could then dramatically reduce the circulation of the SARS-CoV-2 virus and hence limit its ability to generate dangerous new variants.”
Human challenge studies are unique in their ability to investigate and understand the onset and development of disease in a safe and highly controlled environment. They enable scientists to observe and analyse complex interactions between viruses and the human immune system and to identify ways to disrupt and block viral infections.
The five-year Mucosal Immunity in human Coronavirus Challenge (MusiCC) project will be led by Imperial College London, whose specialist researchers have built up years of experience in using human challenge studies to deepen scientific understanding of a range of infectious diseases. In February 2021, Imperial ran the world’s first human challenge study for COVID-19 and currently leads the world’s first human challenge study for non-typhoidal salmonella.
Chris Chiu, Professor of Infectious Diseases at Imperial College London and principal investigator for MusiCC, said: “Coronaviruses typically infect people through cells lining their nose, throat and lungs. Mucosal immunity generated at these surfaces is highly specialised and very different to immune responses in the circulation. Since it directly acts in the place that viruses enter and exit the body, it could be the key to developing vaccines that can block viruses from being able to spread from one person to another.”
“This exciting project enables us to bring together world class expertise in human challenge studies. With our partners, we will build on the fundamental groundwork we’ve already carried out at Imperial, and through our leading expertise and experience in human challenge studies for a range of pathogens, help to develop the next generation of transmission-blocking vaccines.”
As the lead and convener of the consortium, Imperial will work with all MusiCC partners, including, for example, the University of Antwerp’s Vaccinopolis in Belgium, to establish human challenge models that can be used in multiple trial sites. The trials will test potential mucosal vaccine candidates against betacoronaviruses – the sub-family of coronaviruses that includes the SARS-CoV-2 virus that causes COVID-19, several seasonal viruses that cause common colds, and the MERS coronavirus that causes Middle East Respiratory Syndrome.
Using harmonised standard operating procedures, the trials will take place across several sites in the UK, Europe, the United States and Singapore and will each involve a small group of young, healthy volunteers. In the challenge trial, volunteers will first receive either a dose of an investigational vaccine designed to provide mucosal coronavirus immunity or placebo before being intentionally exposed to a calibrated dose of SARS-CoV-2. A model using a seasonal coronavirus called OC43 is also being developed for similar use.
