I was looking at the CDC Vaccine Schedule for children, and it says that many of the things kids are vaccinated for may show no symptoms.
Do any of those diseases –– mainly haemophilus influenzae, Hepatitis A, Polio and Pneumococcal –– stay in a persons system with no symptoms for a long time?
Does getting a vaccine later in life, but after they've been contracted, without exhibiting symptoms, cure the diseases?
And is it known how kids can be carriers for these diseases (i.e. would every sneeze be riddled with these germs)?