The Role of Innate and Acquired Immunity in Susceptibility to Infections in Neonates

Neonates are particularly vulnerable to infections due to the immaturity of their immune systems. Both innate and acquired immunity contribute to their susceptibility, with innate immunity providing the first line of defense and acquired immunity gradually developing after birth. Deficiencies in neonatal phagocytic function, complement activation, and cytokine production impair pathogen clearance, while delayed antibody responses and limited immunological memory further increase infection risk. Factors such as gestational age, maternal health, and microbiota composition significantly influence neonatal immune function. Understanding these mechanisms is crucial for developing targeted interventions, including breastfeeding promotion, maternal vaccination, and microbiome modulation, to enhance neonatal immune defenses. This review highlights the complex interactions between innate and acquired immunity in neonates and discusses potential strategies to reduce infection-related morbidity and mortality.