Hepatitis A is a very prevalent and widespread viral infection that usually affects through water contamination, it also spreads in closed spaces such as schools or day care centres. When a child is infected with hepatitis A he/she is immunised for life, a child will contact the virus usually as it is very widespread but develops only mild reaction to it (fever, body ache etc.).
So as a child reaches the age of five it is usually immunised by its exposure so therefore it is not necessary to provide vaccine for hepitites A after a child reaches the age of 5.