Meningococcal disease from the public health policy perspective.

The incidence and serogroup distribution of meningococcal disease vary by country and over time. In the United States, the annual incidence has been 0.5-1.1/100,000 or about 1400-2800 cases annually with the highest incidence being in infants less than six months of age [1]. Given the availability of conjugate vaccines against serogroups A, C, W-135 and Y and the possible future availability of a group B vaccine, there is now the potential to effectively control meningococcal disease globally. The question then arises as to how public health policy can best serve this goal. MCV-D (Menactra) is not immunogenic in the first six months of life. For this reason, it has been proposed that immunization with this vaccine begin at nine months of age with a second dose at 12 months. This proposal would rely upon indirect or "herd protection" to protect young infants with the highest disease incidence. A second vaccine, MCV-CRM (Menveo), is immunogenic in the first months of life and is under consideration by the FDA for use in infants two months of age and older. MCV-CRM could provide direct protection of this high risk group, but three primary doses plus a toddler booster are required for this approach. In developing public health recommendations to protect infants, policy makers must weigh the additional cost of immunizing with four doses versus the possibility that relying on herd protection using a lower cost immunization schedule beginning at nine months of age may leave young infants unprotected. Optimal control of meningococcal disease will require both the public will and public policy to best serve this goal. The decision as to what ages to target and which schedules to use should not only take into account the cost of the program, but also the severity of the disease and the high level public concern regarding meningococcal disease.