Expanding prevention of invasive meningococcal disease.

Invasive meningococcal disease due to serogroups A, C, Y and W-135 is a serious, vaccine-preventable, worldwide public-health problem. Despite early treatment and advances in medical care, morbidity and mortality rates have essentially remained unchanged. Monovalent, meningococcal serogroup C conjugate (MCC) vaccines against Neisseria meningitidis are effective in children under 2 years of age. MCC vaccines also provide indirect protection to unvaccinated individuals through herd immunity by reducing nasopharyngeal carriage in immunized individuals. Evidence from MCC and other conjugate vaccine initiatives supports immunization initiated as a late infancy/toddler program for prevention of disease caused by serogroups C, Y and W-135. We propose that a meningococcal vaccination program focused on later infancy and the early second year of life should be the preferred approach, providing comparable effectiveness to an early-infant strategy with fewer overall doses and greater cost-effectiveness.