Send us Fan Mail Dr. Ofer Levy, director of the Precision Vaccines Program at Boston Children's Hospital and member of the FDA's Vaccines and Related Biologic Products Advisory Committee, makes the case that vaccines must be tailored to the immune system of the person receiving them — and that immune system changes dramatically from the moment of birth through old age. He explains why preterm infants, who represent 11% of births worldwide, carry an increased risk of infection-related hospital...