Imperial News

Global human challenge consortium to push for next generation of vaccines

by Ryan O'Hare

An international group of researchers specialising in human challenge studies is embarking on a project to develop advanced virus-blocking vaccines.

The global consortium will lay the crucial groundwork needed to develop the next generation of COVID-19 vaccines that could stop SARS-CoV-2 and other coronaviruses from infecting people in the first place.

Led by Imperial College London, the project will be co-funded by US $57m (£44m) from the European Union’s Horizon Europe Programme and CEPI (the Coalition for Epidemic Preparedness Innovations).

The work will see scientific teams and organisations from around the world begin by selecting particular viruses and identifying the best conditions under which to safely induce infection.

Researchers at multiple clinical research facilities will then use these viruses to try to infect healthy volunteers who have received an experimental vaccine.

Next generation vaccines

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.

Professor 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.” 

Professor Chris Chiu, Professor of Infectious Diseases at Imperial College London and principal investigator for MusiCC

Understanding infection

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.

With our partners, we will build on the fundamental groundwork we’ve already carried out at Imperial...to develop the next generation of transmission-blocking vaccines. Professor Chris Chiu Department of Infectious Disease

The five-year Mucosal Immunity in human Coronavirus Challenge (MusiCC) project will be led by Imperial.

Our 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.

Dr Richard Hatchett, CEPI’s Chief Executive Officer, said: “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.

“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.”

Leading the way

As the lead and convener of the consortium, Imperial will work with all partners to establish human challenge models that can be used in multiple trial sites to 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 which cause common colds, as well as the MERS coronavirus – which causes Middle East Respiratory Syndrome.

The trials will follow harmonised standard operating procedures and take place across several sites in the UK, Europe, the United States and Singapore. Small groups of young and healthy 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 either SARS-CoV-2 or other coronaviruses which cause a common cold.

Professor Hugh Brady, President of Imperial College London, said: “I’m delighted to see Imperial’s Professor Chris Chiu leading this consortium. Working with our global partners, we will be able to use human challenge studies to help develop future vaccines that will benefit humanity. This work is a fantastic example of Imperial’s ability to bring people and organisations together to create real-world impact.”

The European Commission’s Laurent Muschel, Head of HERA, and Marc Lemaître, Director-General for Research and Innovation, said: “Research and innovation is an essential part of the jigsaw when it comes to health emergency and pandemic preparedness. Supported through up to €35 million by the European Union’s Horizon Europe programme, MusiCC is an exciting and potential game-changing project, opening up the possibility to target and block viruses, stopping their transmission. Investing in research for health emergency preparedness and response remains a priority for the European Commission to protect the health of our citizens and public health beyond Europe.”

The launch of the MusiCC project follows the Call for Proposals issued by CEPI and co-funded by the European Union to support international research conducting human challenge-based vaccine trials that seek to improve scientific understanding of mucosal immunity against Betacoronaviruses.

Imperial is working with CW+, the official charity of Chelsea and Westminster Hospital NHS Foundation Trust, to develop infrastructure support for human challenge studies. The aim is to create a London hub for future challenge studies.

Our researchers are also collaborating with the National Centre for Infectious Diseases (NCID) in Singapore to better understand the biology of respiratory infection.


The UK is now fully associated to Horizon Europe and Imperial researchers can participate in and lead projects across the programme. To find out more about opportunities in Horizon Europe, please get in touch with the Research Office and the Enterprise Research Impact Management Office.