Back to Hep for a Moment
Someone already pointed out the differences between Hep A and Hep B, but I just wanted to follow up.
Hep B is incredibly difficult to get, and rarely found in kids. Babies are vaxed because they are a captive audience. However, the Hep B "immunity" most likely wears off in 10 - 20 years -- just when they (theoretically) need it the most.
Hep A is more like a severe flu, though my understanding is, it's rarely fatal. The Hep A vax contains some undesirable ingredients, http://www.novaccine.com/specific-va...ne.asp?v_id=45
I hope this is helpful!