BACKGROUND: In 1999, meningococcal serogroup C conjugate (MCC) vaccines were introduced in the United Kingdom for those under 19 years of age. The impact of this intervention on asymptomatic carriage of meningococci was investigated to establish whether serogroup replacement or protection by herd immunity occurred. METHODS: Multicenter surveys of carriage were conducted during vaccine introduction and on 2 successive years, resulting in a total of 48,309 samples, from which 8599 meningococci were isolated and characterized by genotyping and phenotyping. RESULTS: A reduction in serogroup C carriage (rate ratio, 0.19) was observed that lasted at least 2 years with no evidence of serogroup replacement. Vaccine efficacy against carriage was 75%, and vaccination had a disproportionate impact on the carriage of sequence type (ST)-11 complex serogroup C meningococci that (rate ratio, 0.06); these meningococci also exhibited high rates of capsule expression. CONCLUSIONS: The impact of vaccination with MCC vaccine on the prevalence of carriage of group C meningococci was consistent with herd immunity. The high impact on the carriage of ST-11 complex serogroup C could be attributed to high levels of capsule expression. High vaccine efficacy against disease in young children, who were not protected long-term by the schedule initially used, is attributed to the high vaccine efficacy against carriage in older age groups.
BACKGROUND: In 1999, meningococcal serogroup C conjugate (MCC) vaccines were introduced in the United Kingdom for those under 19 years of age. The impact of this intervention on asymptomatic carriage of meningococci was investigated to establish whether serogroup replacement or protection by herd immunity occurred. METHODS: Multicenter surveys of carriage were conducted during vaccine introduction and on 2 successive years, resulting in a total of 48,309 samples, from which 8599 meningococci were isolated and characterized by genotyping and phenotyping. RESULTS: A reduction in serogroup C carriage (rate ratio, 0.19) was observed that lasted at least 2 years with no evidence of serogroup replacement. Vaccine efficacy against carriage was 75%, and vaccination had a disproportionate impact on the carriage of sequence type (ST)-11 complex serogroup C meningococci that (rate ratio, 0.06); these meningococci also exhibited high rates of capsule expression. CONCLUSIONS: The impact of vaccination with MCC vaccine on the prevalence of carriage of group C meningococci was consistent with herd immunity. The high impact on the carriage of ST-11 complex serogroup C could be attributed to high levels of capsule expression. High vaccine efficacy against disease in young children, who were not protected long-term by the schedule initially used, is attributed to the high vaccine efficacy against carriage in older age groups.
Authors: D A Ala'Aldeen; K R Neal; K Ait-Tahar; J S Nguyen-Van-Tam; A English; T J Falla; P M Hawkey; R C Slack Journal: J Clin Microbiol Date: 2000-06 Impact factor: 5.948
Authors: Siamak P Yazdankhah; Paula Kriz; Georgina Tzanakaki; Jenny Kremastinou; Jitka Kalmusova; Martin Musilek; Torill Alvestad; Keith A Jolley; Daniel J Wilson; Noel D McCarthy; Dominique A Caugant; Martin C J Maiden Journal: J Clin Microbiol Date: 2004-11 Impact factor: 5.948
Authors: Robert Cohen; Corinne Levy; France de La Rocque; Nathalie Gelbert; Alain Wollner; Bernard Fritzell; Eric Bonnet; Robert Tetelboum; Emmanuelle Varon Journal: Pediatr Infect Dis J Date: 2006-11 Impact factor: 2.129
Authors: Keith A Jolley; Dorothea M C Hill; Holly B Bratcher; Odile B Harrison; Ian M Feavers; Julian Parkhill; Martin C J Maiden Journal: J Clin Microbiol Date: 2012-07-11 Impact factor: 5.948
Authors: Jennifer R Scott; Jason Hinds; Katherine A Gould; Eugene V Millar; Raymond Reid; Mathuram Santosham; Katherine L O'Brien; William P Hanage Journal: J Infect Dis Date: 2012-04-25 Impact factor: 5.226