Development of newborn and infant vaccines

Abstract

Vaccines for early-life immunization are a crucial biomedical intervention to reduce global morbidity and mortality, yet their developmental path has been largely ad hoc, empiric, and inconsistent. Immune responses of human newborns and infants are distinct and cannot be predicted from those of human adults or animal models. Therefore, understanding and modeling age-specific human immune responses will be vital to the rational design and development of safe and effective vaccines for newborns and infants.

Fig. 1. Distinct humoral and cellular components of the neonatal immune system

Neonatal blood plasma contains a different proportion of key immunomodulatory components than older individuals, including the presence of maternal antibodies, high concentrations of immunomodulatory adenosine, and reduced concentrations of complement, which are important to adaptive immune responses. Differences in neonatal leukocytes include impaired migration and reduced Th1-polarizing responses of neonatal APCs to most TLR agonists. T cell impairments include diminished CD40 ligand expression and reduced IFN-γ production. Neonatal B cells are predominantly transitional and demonstrate impairments in antibody maturation and affinity. CREDIT: C. BICKEL/SCIENCE TRANSLATIONAL MEDICINE

Fig. 2