Take antibiotics to kill Strep bacteria and no need for the 3rd line defenses to form to fight the infection. Big capsule is S. pneumoniae's only virulence factor. The capsule helps with adherence and is antiphagocytic so neutrophils can't do their job. Fluid in the lungs. Edema comes from the inflammatory response to the bacteria colonizing the respiratory tract.
Otitis media is inflammation of the middle ear.
We get S. pneumoniae bacteria from human carriers . Fortunately this infectin is easy to treat with antibiotics. No penicillinase yet in these guys. So cell wall acting like ampicillin or amoxicillin should work fine. Create vegetations - colonies on the valve that constantly seed bacteria into the blood, called bacteremia .