It was explained to me with my firstborn that those people whose babies are exposed to drug abuse in their home, and therefore their babies are higher risk, are not likely to take their babies into the GP for hep B vaccinations so getting them done at birth at least ensures they have one dose. The fact that one dose alone is ineffective seems a slight flaw in this argument.

Another explanation I was given with my second child is the eradication of this disease can only happen by vaccinating the young and letting the disease die with the older people currently affected. However the limited lifespan of the vaccination is another flaw in this argument.

Personally I think vaccinating at risk adults is the way to go, thereby protecting them during the period they are at risk. But maybe I am missing something