Carriage of serogroup C meningococci 1 year after meningococcal C conjugate polysaccharide vaccination

The UK was the first place to Introduce meningococcal serogroup C conjugate (MCC) vaccines. From November, 1999, all people younger than 18 years, about 14 million individuals, were offered MCC immunisation. The uptake rate was more than 70% by November, 2000. We compared the carriage of meningococci in isolates we obtained from 14 064 students aged 15–17 years during vaccination in 1999, with those from 16 583 students of the same age surveyed 1 year later. Carriage of serogroup C meningococci was reduced by 66% (p=0•004). Our results show that MCC vaccines protect against carriage of meningococci that express serogroup C polysaccharide capsules.