ATLANTA — U.S. Health Secretary Robert F. Kennedy Jr.'s new vaccine advisers alarmed pediatricians Wednesday by announcing inquiries into some long-settled questions about children's shots.
Opening the first meeting of Kennedy's handpicked seven-member panel, committee chairman Martin Kulldorff said he was appointing a work group to evaluate the ''cumulative effect'' of the children's vaccine schedule — the list of immunizations given at different times throughout childhood.
Also to be evaluated, he said, is how two other shots are administered — one that guards against liver-destroying hepatitis B and another that combines chickenpox protection with MMR, the measles, mumps and rubella vaccine.
It was an early sign of how the Advisory Committee on Immunization Practices is being reshaped by Kennedy, a leading antivaccine activist before becoming the nation's top health official. He fired the entire 17-member panel this month and replaced it with a group that includes several anti-vaccine voices.
''Vaccines are not all good or bad,'' Kulldorff said. ''We are learning more about vaccines over time'' and must ''keep up to date.''
His announcement reflected a common message of vaccine skeptics: that too many shots may overwhelm kids' immune systems or that the ingredients may build up to cause harm. Scientists say those claims have been repeatedly investigated with no signs of concern.
Kids today are exposed to fewer antigens — immune-revving components — than their grandparents despite getting more doses, because of improved vaccine technology, said Dr. Paul Offit, a vaccine expert at Children's Hospital of Philadelphia.
The American Academy of Pediatrics announced Wednesday that it would continue publishing its own vaccine schedule for children but now will do so independently of the ACIP, calling it ''no longer a credible process.''