Why would a vaccine be administered into the nasal cavity to protect reproductive tract?

A vaccine administered into the nasal cavity would not be to protect the reproductive tract but rather the respiratory tract. The nasal cavity is part of the respiratory system, and vaccines delivered through the nose target mucosal immunity of the upper respiratory tract (including the nasal cavity, mouth, and throat). Mucosal immunity plays a crucial role in preventing or reducing the severity of respiratory infections.

By introducing the vaccine into the nasal cavity, the immune system of the respiratory tract can recognize and develop a targeted immune response against the targeted disease or pathogen. However, vaccines administered into the nasal cavity are typically intended to protect against diseases primarily affecting the respiratory system, not the reproductive tract.