New evidence of decline in disease transmission shows impact of pneumonia vaccine

Pneumococcal vaccine has protected children, families in Navajo Nation and White Mountain Apache Tribe over past fifteen years

Theme(s):
Infectious Disease Prevention

Working together, our Johns Hopkins Center for American Indian Health and the White Mountain Apache and Navajo Nation tribes have gathered valuable new information on the impact of a life-saving vaccine.

The vaccine, known as PCV13 or Prevnar, provides protection against thirteen types of pneumococcus bacteria, which can lead to life-threatening illness, particularly in children and the elderly.

Pneumococcus commonly lives in the back of the nose without causing illness as part of a process known as “carriage,” but can spread to other areas of the body that are normally free of germs. When this occurs, people may become sick and develop a number of dangerous conditions, including meningitis and pneumonia. Additionally, individuals – particularly children – can spread the bacteria to those around them without showing any symptoms themselves.

Our Center monitored the Indian Health Service’s rollout of the PCV13 vaccine beginning in March 2010 and found that the number of children under 5 years of age with the bacteria in the back of their noses decreased significantly. This information means that PCV13 not only protects American Indian children who receive the vaccine, but also their families and friends, as the bacteria can no longer spread from children to those around them.

Our results were recently published in The Pediatric Infectious Disease Journal in an article titled “Impact of the 13-Valent Pneumococcal Conjugate Vaccine on Pneumococcal Carriage Among American Indians.”

In 2015, PCV13 was recommended for adults. Future research will need to be carried out in order to examine changes in pneumococcus carriage among adult populations after they have received the PCV13 vaccine. One challenge to such research is that adults are already less likely to have the bacteria in the back of their noses, making any decrease due to the vaccine smaller and more difficult to confirm. However, our Center and its American Indian partners are committed to working in unison to learn more about the impact of PCV on adults and particularly the elderly.

The work of our American Indian partners to implement the vaccine and gather samples combined with our Center’s expertise in public health analysis have helped show that the PCV13 vaccine can add to the progress already achieved with PCV7. PCV7 protects against fewer types of pneumococcus than PCV13, but produced a significant impact when it was first introduced on the White Mountain Apache and Navajo Nation reservations 15 years ago.

“The vaccine is very effective. We almost never see pneumococcal disease from the strains that are included in the vaccine,” said Katherine O’Brien, director of the International Vaccine Access Center, at the Johns Hopkins Bloomberg School of Public Health, and one of the study’s authors.

Dr. Raymond Reid, a Navajo physician, remembers the toll taken by pneumococcus on Navajo communities before the vaccines and witnessed firsthand the declines in pneumonia, meningitis, and hospitalizations that PCV7 brought when it was first introduced in 2001. However, he noted the importance of communities recognizing that “there is still work to be done” in terms of protecting people from the types of pneumococcus that are not covered by PCV13.

Dr. Reid said that partnering with the White Mountain Apache and Navajo Nation tribes enables tribal health authorities to know what interventions are effective in protecting people from infectious diseases.

“They really understand and appreciate the research being done,” said Dr. Reid.

Story by Will Bellamy

Photo by Ed Cunicelli for Johns Hopkins Center for American Indian Health