Pneumococci immunization against

Kaufman P. Pneumonia in old age active immunization against pneumonia with pneumococcus polysaccharide—results of a six year study. Arch Intern Med 1947 79 518-531. 

Vaccination against influenza and pneumococcus may decrease risk of acute otitis media, especially in those with recurrent episodes. Immunization with the influenza vaccine reduces the incidence of acute otitis media... 

The relevant literature also recommends vaccination against pneumococcus and influenza as well as hepatitis B (unless there is already immunity). 

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