Robert F. Kennedy Jr., secretary of health and human services, appointed eight new members of an expert panel that advises the federal government on immunization policy, including several vocal vaccine critics and one who identifies as an “anti-vaxxer.

It scares me to think of what’s ahead,” said Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy. One of the members of the committee, who spoke on condition of anonymity for fear of reprisals,