U.S. health officials have told more than a half-dozen of the nation’s top medical organizations that they will no longer help establish vaccination recommendations.

Multiple medical groups say they have been barred from working on the Centers for Disease Control and Prevention's panel of vaccine advisers.

Multiple healthcare organizations that have historically helped the CDC's Advisory Committee on Immunization Practices (ACIP) develop vaccine recommendations have been told they can no longer participate in ACIP work groups, leaving the organizations frustrated and worried about what will happen next.