In industrialised countries, the highest incidence of meningococcal disease is observed in young children, while colonisation is most common in teenagers and young adults. The prevalence of meningococcal carriage is a poor predictor of disease risk because other factors, including host susceptibility and the invasive potential of the organism, are important. The natural history of meningococcal infection is dominated by transmission between carriers and disease is a relatively rare event. As the experience with meningococcal serogroup C conjugate (MCC) vaccines illustrates, vaccines that can influence transmission in addition to disease will have much greater population impact. In the UK, excellent control of serogroup C disease continues, largely because of sustained herd immunity. The ability of other meningococcal conjugate and candidate protein vaccines to reduce carriage, and indeed the effect of MCC vaccines in different epidemiological contexts, is not known, Given the potential magnitude of herd immunity that can be achieved, carriage studies should be considered as an important component of vaccine evaluation. Outcomes of interest include the prevalence of carriage before and after immunisation. This information is highly relevant in terms of optimising vaccine strategy and determining the likely cost-effectiveness of immunisation programmes. For example, if a vaccine has no effect on carriage, routine infant immunisation may be preferred, whereas for a vaccine that is able to prevent carriage, strategies that include a catch-up campaign and target the age-group which is driving transmission may be much more attractive.
|Translated title of the contribution||Meningococcal carriage as a correlate of protection|
|Title of host publication||Neisseria Vaccines Conference 2009. Varadero, Cuba|
|Publication status||Published - May 2009|