Pneumococcal vaccine is an immunization against Streptococcus pneumoniae, a bacterium that frequently causes meningitis and pneumonia in the elderly, and people with chronic illnesses. Pneumococcal pneumonia accounts for 10% to 25% of all pneumonias.
Review Date 8/6/2021
Updated by: David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.