DR. FREED is a professor of pediatrics at the Division of General Pediatrics, University of Michigan, Ann Arbor, and director of the Child Health Evaluation and Research Unit, University of Michigan, Ann Arbor. He is also a member of <i>Contemporary Pedia
The new conjugate vaccine MCV4 promises longer duration of immunity and, perhaps, greater clinical efficacy than the polysaccharide vaccine MPSV4. Questions remain about booster doses, vaccinating young children, and safety.