For decades, there was no licensed vaccine for prevention of endemic capsular group B meningococcal disease, despite the availability of vaccines for prevention of the other most common meningococcal capsular groups. Recently, however, two new vaccines have been licensed for prevention of group B disease. Although immunogenic and considered to have an acceptable safety profile, there are many scientific unknowns about these vaccines, including effectiveness against antigenically diverse endemic meningococcal strains; duration of protection; whether they provide any herd protection; and whether there will be meningococcal antigenic changes that will diminish effectiveness over time.
