The U.K. is set to conduct the globe’s first study in which healthy volunteers will be intentionally exposed to the coronavirus.

The U.K. Department for Business, Energy and Industrial Strategy said in a statement Wednesday that the research, known as a human challenge study, was approved and will begin within a month.

The first stage of the government-funded trial will include as many as 90 volunteers between the ages of 18 and 30 being exposed to a small dose of the coronavirus in a controlled setting. The second phase, which has yet to receive approval, will involve injecting another group of volunteers with a vaccine and then exposing them to the virus.

The U.K. government said only vaccines that “have proven to be safe in clinical trials” will be used.

Advocates of such studies say they are quick ways to determine a vaccine’s effectiveness, though they remain controversial because they involve purposefully infecting people with a possibly lethal virus.

“Researchers and scientists around the world have made incredible progress in understanding Covid-19 and developing critical vaccines to protect people,” said U.K. Business Secretary Kwasi Kwarteng.

“While there has been very positive progress in vaccine development, we want to find the best and most effective vaccines for use over the longer term. These human challenge studies will take place here in the UK and will help accelerate scientists’ knowledge of how coronavirus affects people and could eventually further the rapid development of vaccines.”