Study to Eliminate Hib Carriage in Rural Alaska Native Villages

Hib disease rates in rural Alaska before introduction of HIb conjugate vaccine were among the highest in the world. Since vaccine introduction, rates have fallen by 90% but the disease has not been eliminated. This study is designed to test one possible means of eliminating Hib carriage and thus to eliminate person to person transmission and invasive disease. The objective of this study is to evaluate the effectiveness of community-wide use of Hib conjugate vaccine for eliminating oropharyngeal Hib carriage in rural Alaska villages. Secondary objectives include: * Determine risk factors for Hib OP carriage including demographic characteristics, and immunologic characteristics (antibody level and function). This will be accomplished through a case-control study described below. * Measure antibody response to Hib conjugate vaccine among adults who have not previously received Hib vaccine. This will be accomplished through a cohort study of participating adults in the vaccine intervention communities.