The CDC recommends that adults over the age of 65 receive one dose of a pneumococcal vaccine. This vaccine can prevent infections by the bacterium Streptococcus pneumoniae. This bacterium can cause diseases such as pneumonia, meningitis, blood infections, sinus infections, and ear infections. Additionally, persons age 19 to 64 who suffer from a weakened immune system or chronic lung, liver, or heart disease may benefit from this vaccine. Other conditions that may warrant pneumococcal vaccination include alcoholism, smoking, diabetes, and leukemia. Furthermore, persons with cochlear implants are also at risk for pneumococcal infections and may benefit from vaccination.