Immunoglobulin A (IgA) is a type of antibody that plays a crucial role in the immune system. It is primarily found in mucosal areas, such as the gut, respiratory tract, and saliva, helping to protect these surfaces from infections. IgA is essential for neutralizing pathogens and preventing their entry into the body. There are two main forms of IgA: serum IgA, which circulates in the bloodstream, and secretory IgA, which is present in secretions like breast milk and mucus. This antibody is vital for maintaining mucosal immunity and is particularly important for infants, as it helps protect them from infections during early development.