'Challenge trials' set to infect volunteers with coronavirus to help speed up creation of vaccine

Volunteers could soon be deliberately infected with coronavirus in trials to speed up the development of a vaccine and discover whether people are protected if they have already had the disease.

In a groundbreaking trial, scheduled to begin in January at the Royal Free Hospital in London, patients will be inoculated with a vaccine developed by Imperial College and then exposed to coronavirus.

"Challenge trials" are controversial, but can give a quick answer about whether a vaccine is effective, and several Nobel laureates have called for them to take place.

Oxford University is also intending to use a similar "challenge trial" to test whether people have protective immunity from the disease if they have been previously infected.

Both groups of researchers are currently hunting for a "salvage therapy" which would be given as a last resort if the vaccine did not work before they can begin the trials, and will need approval.

Several drugs, including remdesivir and dexamethasone, are now being used to treat coronavirus. They can limit the severity of the disease and lower the chance of death.

The trials will be funded by the Government (watch Boris Johnson visiting a coronavirus vaccine research centre in Oxford in the video below), and an announcement is expected soon.

Commenting on the reports, Dr Claire Waddington, a clinical lecturer in infectious disease at the University of Cambridge, said: "As we gain more understanding of Covid-19, we are increasingly in a position to identify those people for who Covid-19 infection is a mild illness, and these people could safely participate in a controlled human infection study.

"Such a model could give us some extremely useful information on how the immune system responds to Covid and what responses are protective, as well as providing a model for early testing of candidate vaccines."

The Imperial trial is being run by hVivo, a spin-off company from Queen Mary University of London. Already, roughly 2,000 people have signed up to take part in challenge studies in Britain through the group 1Day Sooner.

Those testing the vaccine will be given the jab and then wait a month for antibodies to build. The volunteers will then be exposed to the virus.

Currently, vaccines are tested at population level, so scientists look to see whether a smaller percentage of people are infected than would be expected in the vaccine arm of the trial compared to a control group.

However, worldwide lockdowns have meant the virus has been very low in the community in recent months, and scientists have struggled to get enough data to know whether their vaccines are working.

Oxford University has been forced to move some of its vaccine testing to South America and South Africa, although it is expecting results back soon.

A Government spokesman said: "We are working with partners to understand how we might collaborate on the potential development of a Covid-19 vaccine through human challenge studies. These discussions are part of our work to research ways of treating, limiting and hopefully preventing the virus so we can end the pandemic sooner."