closeup of hand holding syringe pulling fluid from vialEven though FDA-authorized coronavirus vaccines are now widely available, writes Hannah Weinberger (@Weinbergrrrrr) for Crosscut, people continue to participate in clinical trials of new COVID-19 vaccines. Her story discusses a new University of Washington clinical trial of an experimental vaccine that its manufacturer hopes will provide stronger protection than existing vaccines. And she introduces us to some of the participants who have volunteered to help science keep pushing forwardImage: U.S. Air Force