Residents in Long Beach, California, drive to a COVID-19 testing site located on a parking lot as the state sees a spike in the number of cases.

At a beach nearby, residents enjoy sport activities, with some wearing face masks and others indifferent.

"My own personal concern is we’re seeing a lot of younger folks now and that they in turn will carry on and infect other people that are more vulnerable," says Susan Butler-Wu, professor of clinical pathology at USC.