Free vaccines meant for children as part of a U.S. government program may have been stored at the wrong temperature, which could make them less effective, according to a report released on Wednesday.
The report also found that both expired and unexpired vaccines had been stored together in some doctors' offices and clinics, which could potentially lead to mistakes in giving the wrong version, the Office of the Inspector General (OIG) in the Department of Health and Human Services said.
The findings could apply to a much wider lot of vaccines, since many of the same clinics that provide free immunizations for low-income children also give shots to insured children.
