Pneumococcal infections used to be readily treatable by antibiotics, but this is no longer the case. While some types of pneumococcus remains easy to treat, many types of pneumococcus bacterium have developed resistance to antibiotics. Stronger antibiotics must be used to treat these tough infections. It is not unforeseeable that sooner or later some strains of this bacterium will develop resistance to all antibiotics, rendering all treatment futile.

Since the pneumococcal vaccine became available, the pneumococcus bacterium has become less resistant to antibiotic treatment because the vaccine is targeted against those types of bacteria that are most likely to develop resistance to treatment.