Efficacy of meningococcal serogroup C conjugate vaccine in teenagers and toddlers in England.

The UK was the first country to use meningococcal serogroup C conjugate (MCC) vaccines, which were licensed on the basis of immunogenicity and safety data but without a formal efficacy study. Increased surveillance during the first 9 months since introduction has shown that short-term efficacy of the MCC vaccine in England was 97% (95% CI 77-99) for teenagers and 92% (65-98) for toddlers. These early results confirm the superiority of MCC over plain C polysaccharide vaccines, which are ineffective in young children.