US grapples with whether to modify COVID vaccine for fall

  • FILE - A health worker administers a dose of a Moderna COVID-19 vaccine during a vaccination clinic in Norristown, Pa. on Dec. 7, 2021. In a reversal for President Joe Biden, a federal appeals court in New Orleans on Monday, June 27, 2022, agreed to reconsider its own April ruling that allowed the administration to require federal employees to be vaccinated against COVID-19. (AP Photo/Matt Rourke, File)

U.S. health authorities are facing a critical decision: whether to offer new COVID-19 booster shots this fall that are modified to better match recent changes of the shape-shifting coronavirus.