Approximately 800,000 swine flu shots for children have been recalled, including 15,000 lots that were distributed in Pennsylvania. Testing found that the shots, intended for children ages six months to three years, have lost some strength.
The vaccinations, manufactured by Sanofi Pasteur, were distributed across the country last month and most have already been administered. Tests conducted before the shots were shipped showed that they were strong enough. However, tests done weeks later indicated that their strength had decreased and was slightly below required levels. The reason for the change is not yet known.
Children in the six-month to three-year age group are supposed to get two doses of the H1N1 vaccine. For now, health officials don't believe that children need to get vaccinated again, even if they received two doses from the same lot. Since the vaccine became available in October, manufacturers have released 95 million doses for distribution.