Influenza, COVID-19, and RSV Vaccinations for Immunocompromised Children and Household Contacts.

Immunocompromised pediatric patients, including hematopoietic cell and solid organ transplant recipients, those undergoing chemotherapy for malignancy, and those receiving biologic response modifiers for autoimmune or inflammatory conditions, are at risk for severe disease from vaccine-preventable respiratory viral infections such as influenza, SARS-CoV-2 (COVID-19), and respiratory syncytial virus (RSV). These children face higher rates of hospitalization, intensive care admissions, and mortality, reflecting contributions from an immature immune system, absence of immunologic memory, and/or increased environmental exposures. Immunization recommendations for immunocompromised children are largely extrapolated from studies conducted among healthy children and/or immunocompromised adults due to a paucity of primary data on immunological responses and vaccine efficacy in immunocompromised children. Trends in vaccine hesitancy in the general population, ongoing transmission of respiratory viral infections in the community, and suboptimal vaccination rates among immunocompromised children and their household contacts further compound the risk for this vulnerable population. As the number of children with immunocompromising conditions expands, it is imperative that primary care practitioners and subspecialists who care for immunocompromised children ensure appropriate immunizations are provided to these patients and their household and community contacts. We will review available data supporting the current guidelines regarding vaccine dosing, scheduling, and formulations to prevent influenza, COVID-19, and RSV infections in immunocompromised children. Furthermore, we highlight key knowledge gaps and areas of current investigation aimed at improving respiratory viral vaccine immunogenicity and optimize protection.