By Mick Krever and Phil Black, CNN
London (CNN) The UK government has signed a contract for the first human challenge studies for the novel coronavirus, in which healthy volunteers are deliberately infected with the virus in a controlled setting, and some receive an experimental vaccine.
Up to 19 volunteers at a time will take part in the tests, to be held at the Royal Free Hospital in London, which houses a Biosafety Level 3 ward. They will be run by hVIVO, a medical research company that specializes in running challenge trials, in partnership with Imperial College London.
These clinical trials will be a little different from most.
For the current Covid-19 vaccine candidates that are in Phase 3 — the final stage of testing — tens of thousands of volunteers are given an experimental vaccine and then released to live their everyday lives; researchers assume that a certain percentage of them will be exposed to the virus naturally.
In a challenge trial, by contrast, participants are deliberately dosed with virus.
Proponents of challenge trials say that they are more efficient, requiring far fewer volunteers — likely in the hundreds — because researchers know for certain that everyone will be exposed to the virus, and that they can deliver scientific data more quickly.