What happens if a child is administered double dosage of Hepatatis A vaccine in span of 3 months ?
An extra dose of Hepatitis A should not be harmful. Though, it shall not be counted in the schedule as it will not be effective. Re-vaccination with a dose should be done after 6 months have passed following the extra dose. For more info see https://www.vaccinebox.com/types-of-vaccines/hepatitis-a-vaccine/