Pneumonia is a common infectious disease of the respiratory system. For the elderly who are frail, infants and young children who repeatedly suffer from pulmonary infections, and adults with immune deficiencies, it is an option to get vaccinated against pneumonia. Generally, antibodies are produced in the body 2 to 3 weeks after vaccination, which may protect against most types of pneumococcal bacteria. Different pneumonia vaccines vary in the duration the antibodies last in the body, with most lasting about one year. For bivalent and trivalent pneumonia vaccines, the immune protection can last about five years.