The epidemiologic evidence underlying recommendations for use of pneumococcal polysaccharide vaccine among American Indian and Alaska Native populations.

Alaska Native and some American Indian (AI/AN) populations suffer disproportionately high rates of invasive pneumococcal disease (IPD) in both the pediatric and adult populations compared to the general U.S. population. Two pneumococcal vaccines are currently available in the U.S.: a 23-valent pneumococcal polysaccharide vaccine (PPSV23), available since 1983 and recommended for the elderly and those over 2 years of age with underlying medical conditions, and a 13-valent pneumococcal conjugate vaccine (PCV13), used in the routine infant immunization schedule since 2010. The U.S. Advisory Committee on Immunization Practice (ACIP) previously recommended use of PPSV23 for persons living in special environments or social settings, including AN and certain AI persons 2-64 years of age, on the basis of higher disease rates. The recommendation for routine PPSV23 use among AI/AN persons <65 years of age, regardless of underlying conditions, was removed in 2008, although the option for use among those 50-64 years of age living in areas with high pneumococcal disease rates was maintained. The rationale for the revised recommendations lay in the recognition that much of the excess disease burden occurs among those with an existing medical indication for PPSV23. Other considerations for the change were the potential risks of giving multiple PPSV23 doses and the considerable heterogeneity in pneumococcal disease risk among American Indian populations requiring a more tailored approach to local recommendations based on local epidemiology.