WASHINGTON (AP) — With President Joe Biden vowing to get younger students back to the classroom by spring, some experts want the U.S. to refocus its COVID-19 testing system less on medical precision than on mass screening that they believe could save hundreds of thousands of lives. As vaccinations slowly ramp up, they say turning to millions more rapid tests that are cheaper and faster but technically less accurate than the predominant genetic tests may improve the chances of identifying sick people during the early days of infection, when they are most contagious. The case for widescale rapid testing is getting a boost from universities and school systems that have used the approach to stay open through the latest waves of the pandemic.