Letter sent to parents of children treated at Brierley Medical Practice . Warns vaccines were stored at the wrong temperature and while they were not harmful , they may have been less effective than normal . NHS England said a total of one children are affected by the mix up . Also included vaccines to protect against polio , whooping cough .
Letter sent to parents of children treated at Brierley Medical Practice . Warns vaccines were stored at the wrong temperature and while they were not harmful , they may have been less effective than normal . NHS England said a total of 515 children are affected by the mix up . Also included vaccines to protect against polio , whooping cough .