The U.K. government is considering carrying out the first studies that would deliberately expose healthy people to the coronavirus in a bid to accelerate the development of a vaccine.

The idea of challenge trials has gained momentum as the pathogen has spread around the world, sparking a debate over what kind of sacrifice is acceptable and the benefits the tests could bring. A growing number of volunteers have signed up to take part in such studies should researchers decide to proceed.

“We are working with partners to understand how we might collaborate on the potential development of a Covid-19 vaccine through human-challenge studies,” a government representative said Wednesday in an email. “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.”

Waiting for participants to become exposed to the illness to figure out whether a vaccine works can take months or even years. Challenge tests can hasten the work by placing volunteers in the path of the virus, though scientists are still learning about a pathogen that has killed almost 1 million people in just months.

Such tests also raise ethical questions about exposing people to a potentially fatal virus, and whether some test subjects would receive a placebo for control purposes.

The government declined to provide further details, including about which vaccines would be involved. U.K.-funded studies are expected to begin in January at a facility in London, the Financial Times reported earlier. In Britain, the University of Oxford is working with AstraZeneca Plc on a Covid vaccine, one of the front-runners in the global effort. Imperial College London is also working on an experimental inoculation.

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