Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection (LRTI) among infants and young children, resulting in annual epidemics worldwide. Children with congenital or acquired immunodeficiencies, transplant recipients, and those receiving immunosuppressive therapy are at increased risk for severe RSV-associated disease resulting in prolonged hospitalizations, admissions to the intensive care unit (ICU), and the need for mechanical ventilation. Nirsevimab is not a vaccine, but a monoclonal antibody. Monoclonal antibodies are laboratory-made proteins that mimic the immune system's ability to fight off harmful antigens such as viruses. Nirsevimab is being developed as a cost-effective long acting product to protect all infants from RSV disease in a once-per-RSV-season dosing as opposed to the only current FDA approved RSV specific monoclonal antibody which requires 5 monthly injections. Approximately 100 subjects will be enrolled. Subjects will be followed for approximately 1 year after a single dose of nirsevimab and will have 4 in person visits and numerous telephone check ins during the year of follow up.

The purpose of this study is to evaluate how effective MEDI8897 is at preventing lung disease caused by Respiratory Syncytial Virus (RSV) and to evaluate the safety and tolerability of MEDI8897 in healthy infants compared with placebo. A placebo is a saline solution that looks like the study drug but it does not contain the active ingredient.

The TRANSFORM network is focused on improving child health outcomes in SC through research on conditions of highest priority for future generations. These include conditions like asthma, autism, diabetes, obesity and early childhood outcomes. To accelerate research study recruitment activities for future projects that TRANSFORM sites may participate in, the TRANSFORM network sites will create a research recruitment registry of families interested in volunteering for research. Participants will enter their own as well as their child(ren)'s information into the electronic registry which can be used to identify people to contact for future studies.

We will combine state-of-the-art brain imaging techniques in 140 Single Ventricle Reconstruction Trial (SVR) III patients and 100 control subjects with innovative brain connectome or "graph" analyses to determine if brain connectivity graph measurements will provide novel neuroimaging biomarkers for neurodevelopmental disabilities and improve our understanding of their inciting mechanisms in the SVR survivors. Only 6 of the SVR III patients and no controls will be enrolled at MUSC.