Immunocompetent: mild, if any, symptoms consisting of viral syndrome, cough
Immunocompromised (e.g. AIDS, bone marrow transplant, etc.): can have severe respiratory distress, sepsis
CMV pneumonia
Tuberculosis
Pertussis
Influenza
Croup
HIV pulmonary complications
Atypical pneumonia
Pneumocystis jirovecii pneumonia