FluGen will evaluate its influenza vaccine in a trial of 100 people later this spring, the company announced recently.

“Our vaccine contains a live virus that infects you but cannot make you sick,” FluGen CEO Paul Radspinner said in a statement. “We will measure how well our vaccine protected against the flu challenge, based on infection and symptoms, and we’ll look at a broad range of safety indicators as well.”

According to a release, half of the trial participants will get a saline squirt in the nose and the other will get FluGen’s vaccine. The goal is to measure how well the vaccine protects against a dose of live flu virus.

The study will take place in Belgium. A test in healthy adults, completed in 2016, showed no warning flags related to safety.