If an infant got a dose of the adult formulation of HepB in error, should the dose be counted? When should the next dose be scheduled for this infant? Do we need to be concerned about a possible adverse event?

If an infant received an adult dose of HepB (contains twice the antigen in a dose of the pediatric formulation), the dose can be counted as valid and does not need to be repeated. Hepatitis B vaccines are very safe vaccine and no unusual adverse events would be expected because of this administration error. The next (age appropriate) dose should be given on the usual schedule.