WASHINGTON (AP) — U.S. health officials say that most fully vaccinated Americans can skip testing for COVID-19, even if they were exposed to someone infected. That new guidance was announced last week but was all but eclipsed by the new, more relaxed guidelines on masks. Experts say the waning importance of testing reflects a new phase of the pandemic. People who are fully vaccinated face little risk of developing serious illness or passing the infection onto others. Experts now say that aggressively testing vaccinated people can lead to unnecessary worry and disruption at work and school.