As confidence in the C.D.C. wanes, states are asserting more control over their vaccine policies, creating a fragmented public-health system. Last week, former officials from the Centers for Disease Control and Prevention warned members of Congress that Robert F. Kennedy, Jr., the Secretary of Health and Human Services, was endangering the nation's welfare by dismissing evidence and expertise in favor of his own vaccine skepticism. Kennedy "censored C.D.C. science, politicized its processes, and stripped leaders of independence," Debra Houry, the agency's former chief medical officer, said in a hearing this past Wednesday. The following day, the Advisory Committee on Immunization Practices ()--the scientific panel that influences U.S. vaccine policy more than any other body--began a chaotic and contentious two-day meeting about updating the country's vaccination recommendations. The committee's members had been handpicked by Kennedy, some of them joining just days before. Several of's decisions, which were announced last week, will have limited practical impact.

To the editor: Regardless of the vaccine debate, making sweeping medical conclusions without examining a patient is both unethical and negligent. I think Dr. Bob Sears has let his ideology trump medical practices. To the editor: I think there are two things to keep in mind when choosing a doctor for your child. First, choose one that relies on competent, vetted research to best help your child. Anyone spouting "theories" that have not been supported by current research, or in this case, have been refuted by research, puts a child at risk.