For decades, the federal childhood vaccination schedule has stood as one of the more durable achievements of American public health — a framework built slowly through scientific consensus and refined by expert review. Now, the Department of Health and Human Services has opened a formal inquiry that many observers read as the first step toward revising that foundation, prompting state officials and advocacy groups to mount an early defense. The tension at the heart of this moment is an old one: who holds the authority to define what protects a child's health — the clinician, the committee, or t