Infectious Disease Control
Native Americans in the southwest United States have among the highest rates of severe disease caused by the bacterium, Streptococcus pneumoniae (pneumococcus). Diseases caused by pneumococcus include pneumonia, meningitis and infections of the blood, ear and sinus. There are more than 90 different types of pneumococcus.
Prevnar7, a pneumococcal vaccine licensed in 2001 for children, protected against 7 of the 90 types. The currently available vaccine, Prevnar13, replaced Prevnar7 in 2010. Prevnar13 protects against an additional 6 types and is recommended for routine use among children <5 years, adults ≥65 years, and for persons 6 through 64 years of age who have certain medical conditions such immunodeficiencies. Use of Prevnar7 and Prevnar13 in children resulted in a >95% decline in disease caused by pneumococcal types covered by the vaccine.
In spite of vaccine use, severe disease caused by pneumococcus persists in Native American populations. The majority of disease is caused by types not covered by the vaccine. An investigational vaccine has been developed that includes the 13 types of pneumococcus in Prevnar13 plus an additional two types. We conducted a study on the Navajo Nation and White Mountain Apache Tribal lands to measure the immune response to the vaccine in nearly 600 adults 18-49 years of age. Participants were randomized to receive either the investigational vaccine or Prevnar13.
The results of this study help understand how well the investigational vaccine can provide protection against pneumococcal disease in this population.