A world-first human challenge trial is set to commence in weeks after a UK clinical trial ethics committee approved the controversial study. The research will ultimately look to test vaccine efficacy, however, the first step will involve exposing young subjects to small volumes of the virus to understand the lowest dose that leads to COVID-19.
Early on in the pandemic the topic of human challenge trials was suggested as a way to speed up vaccine development. The idea of exposing healthy volunteers to a pathogen in order to learn more about infection or test a vaccine is not new, but it is rarely deployed and always ethically controversial.
As we learned more about this novel coronavirus over the course of 2020 calls for human challenge trials increased and in October last year the UK government announced a large investment into running these trials. Now, months later, an Ethics Committee convened by the UK Health Research Authority has formally approved an initial study that should commence in the coming weeks.
This initial trial is the first stage of any human challenge research, and it is called a virus characterization study. Before scientists can test vaccine efficacy they need to empirically investigate the precise dose of virus to use in future research.
To do this, 90 healthy volunteers will be recruited and exposed to very low doses of virus in order to home in on the safest and smallest volume of virus that consistently leads to the development of COVID-19. Once this has been determined future studies can then investigate vaccine efficacy in controlled conditions.
The subjects recruited will be young, aged between 18 and 30, carefully recruited to make sure they are at the lowest risk for any disease-related complications. They will be exposed to the virus in a purpose-built quarantine facility in London.
Andrew Catchpole, chief science officer at hVIVO, an organization that has conducted human challenge studies for over 30 years, suggests this initial virus characterization phase is not just a cursory stage of research. He says it will deliver valuable new insights into the earliest stages of infection. This is data scientists have been unable to gather so far in the pandemic.
“We will start to see useful results very quickly after the commencement of the study,” says Catchpole. “From the moment we inoculate someone with this virus, we will learn important information about disease progression and treatment. This crucial data feeds directly back into how to develop effective vaccines and better treatments because they identify what type of immune response needs to be triggered.”
The virus being investigated in this upcoming human challenge study will be one of the early strains of SARS-CoV-2, found circulating in March 2020. Although more recent mutations are becoming dominant around the world, the researchers behind this study say not enough is known about the new variants to determine safety profiles sufficient for ethics approval.
Chris Chiu, chief investigator on the trial, from the Department of Infectious Diseases at Imperial College London, is calling now for volunteers in the UK. The trial is expected to start within weeks.
“We are asking for volunteers aged between 18 and 30 to join this research endeavor to help us to understand how the virus infects people and how it passes so successfully between us,” says Chiu. “Our eventual aim is to quickly test which vaccines and treatments work best in beating this disease.”
If you are young, healthy, live in the United Kingdom, and are interested in taking part, you can register details at UK COVID Challenge.