The National Institutes of Health (NIH) is offering a funding opportunity titled "Early Immune System Development and Ontogeny" under the R01 Clinical Trial Optional grant program. This initiative aims to investigate the mechanisms of early immune development in children, particularly focusing on those with in-utero exposure to HIV or Anti-Retroviral Therapeutics (ART), and includes research on maternal and paternal immune statuses, immune cell development, and environmental influences. The program is significant for advancing laboratory research and clinical trials that enhance understanding of immune maturation in neonates and children. Eligible applicants can receive up to $400,000 per year for a maximum project duration of four years, with applications opening on April 7, 2025, and closing on January 8, 2029. For further inquiries, interested parties can contact NIH Grants Information at grantsinfo@nih.gov.