Levers of Prevention

Beginning in November, Stop Pneumonia is featuring a series of excerpts from the 2016 Pneumonia and Diarrhea Progress Report: Reaching Goals Through Action and Innovation. The annual report identifies the 15 countries with the greatest number of deaths from pneumonia and diarrhea among children under the age of five. In addition, the country profiles, Q&As, and essays focus on how to save children’s lives through action and innovation. The report is produced by the International Vaccine Access Center, at the Johns Hopkins Bloomberg School of Public Health.

The full report can be read online here.

2016 Pneumonia and Diarrhea Progress Report

Levers of Prevention

Immunization: The Most Effective Way to Lower Pneumonia Mortality

By Keith Klugman, MD, PhD, Director for Pneumonia, Bill & Melinda Gates Foundation

While there are a number of levers that can be used to prevent pneumonia, by far the largest is vaccines—more specifically, conjugate vaccines.

Over the last decade, we have seen a dramatic rollout of the pentavalent vaccine to infants, which includes the Hib conjugate vaccine and, more recently, pneumococcal conjugate vaccine. These two vaccines aim to prevent Hib and pneumococcal disease. The significant impact of these vaccines on residual pneumonia mortality has been proven, and researchers are working to evaluate the magnitude of that impact.

Other levers of prevention include promotion of breastfeeding and trying to reduce indoor and outdoor air pollution. However, there are still large questions about the extent to which one can impact indoor air pollution by altering the source of energy in the home. The Bill & Melinda Gates Foundation (Gates Foundation) is supporting a large National Institutes of Health study looking at the switch from wood-based energy to gas, and the impact that switch has on infant pneumonia. Looking into the future, we hope to see continued rollout of pneumococcal conjugate vaccine. Current discussions in India about introducing PCV into high-burden states is very exciting. However, despite the success of Gavi, there are large numbers of children in low-middle income countries that do not have access to the vaccine. In particular, Indonesia and China do not currently have plans for PCV rollout.

Innovation is needed in a number of areas. First, although vaccines are available, we need innovative solutions to make them more affordable. Another major issue for pneumococcal conjugate vaccines is vaccine serotype type replacement. Existing vaccines only cover 70-75% of the pneumococcal burden in developing countries. The combination of strains that are not covered, and some degree of replacement, means that as much as a third of the pneumococcal pneumonia burden still remains. We need innovation in either expanded conjugate vaccines, or approaches that are not type specific, to prevent the residual burden of pneumococcal disease.

Additionally, as post-neonatal mortality is reduced with scale-up of interventions, the fraction of infant mortality attributable to pneumonia among neonates is increasing. The major viral cause of pneumonia hospitalization in very young infants is respiratory syncytial virus (RSV). Since there’s neither a vaccine nor a practical passive antibody approach that could be used on a routine basis, especially one that is affordable for low-resource countries, we are looking to support the development of vaccines that could protect against RSV mortality. Two potential ways forward are investigating if maternal immunization can reduce RSV in the very young; and the second, a single injection of long lasting antibody given to infants intramuscularly that could protect them for the entire RSV season.

Investing in efforts to improve immunization that prevents more bacterial and viral causes of pneumonia is a big task, yet a critical next step. Building upon existing knowledge with innovative approaches to improve vaccine effectiveness, access, and affordability will save more young lives around the world.

Keith Klugman, MD, PhD has chaired or served on numerous expert committees for WHO and the CDC, among other U.S. and international organizations, and has published more than 550 scientific papers on the subjects of pneumonia, meningitis, antimicrobial resistance, and vaccines for bacterial pathogens, which have been cited more than 25,000 times to date.