WASHINGTON : The US government issued simplified rules for developers of coronavirus tests to promote serial screening, a process in which the same individual is tested multiple times within a few days, the Food and Drug Administration (FDA) said."Today, we are providing information for test developers about a streamlined path to emergency use authorization," the FDA said in a press release on Tuesday. "This [path] applies to developers of molecular and antigen tests, for use in serial testing programs, as well as at-home tests for use in a serial manner outside of a testing program."Serial testing is used to detect asymptomatic coronavirus infections that fail to show up in a single test, the release said.