The Centers for Disease Control and Prevention notified doctors about the anamnesis Tuesday. The anamnesis involves about 800,000 doses fabricated by Sanofi Pasteur. The doses are pre-filled syringes advised for adolescent children, ages 6 months to about three years.
Health officials recommend children those ages get two doses, spaced about a month apart.
Health officials say it's not clear how many doses have already been given, but they don't think children need to be re-vaccinated. The lots passed potency tests when they were first shipped, but tests indicate the potency waned after.