Mixed respiratory vaccine is a mixture of killed bacteria. It is used to strengthen the immune system to help your body fight chronic infections. Mixed respiratory vaccine is used in people with chronic infections such as infectious asthma, chronic sinusitis (inflamation of the sinuses), nasal polyps, ear infections, and other upper respiratory tract infections. The vaccine works by exposing you to a small dose of the bacteria mixture, which causes the body to develop immunity to certain diseases. This vaccine will not treat an active infection that has already developed in the body. Like any vaccine, the mixed respiratory vaccine may not provide protection from disease in every person.