Synagis, also known by its generic name palivizumab, is a monoclonal antibody medication primarily used to prevent severe respiratory syncytial virus (RSV) infections in infants and young children who are at high risk. RSV is a virus that causes respiratory infections, which can be particularly severe in premature infants, those with certain heart conditions, or children with weakened immune systems. Synagis works by providing passive immunity, meaning it supplies the body with antibodies that are designed to recognize and neutralize the virus, thereby helping to prevent infection. It is administered through intramuscular injections, typically given before the start of the RSV season and continued monthly throughout the season to maintain protection. Synagis is a critical preventive measure for vulnerable populations, aiming to reduce hospitalizations and complications associated with severe RSV infections.