"This study shows how pneumococcal vaccination of children benefits the whole community. This is an important part of the case for accelerated introduction of pneumococcal vaccination in the developing world where pneumococcal disease kills a child every minute of every day."
- Orin Levine,
PneumoADIP Executive Director
Read the Full CDC Report
Centers for Disease Control and Prevention. “Direct and Indirect Effects of Routine Vaccination of Children with 7-Valent Pneumococcal Conjugate Vaccine on Incidence of Invasive Pneumococcal Disease – Unites States, 1998-2003.” MMWR 2005; 54: 893-897.
What is herd immunity?
Herd immunity occurs when a large enough portion of a population is vaccinated against a microbe (such as S. pneumoniae) – reducing transmission of disease (such as pneumonia, meningitis, sepsis) among people; thereby, unvaccinated people have a lower chance of becoming infected by that microbe.
Routine pneumococcal vaccination of young children protects both vaccinated children and unvaccinated groups
Atlanta, U.S.A. – September 16, 2005. The Centers for Disease Control and Prevention (CDC) published an exciting report that provided a big-picture look at the public health impact of routine pneumococcal conjugate vaccine (PCV) use in the U.S., based on multi-year data from CDC’s Active Bacterial Core surveillance (ABCs).
This CDC report:
Dr. Deron C. Burton, the lead author of this report, spoke with PneumoADIP.
How significant is this report from a U.S. public health point of view?
Very significant. This report documented the dramatic decline in disease following routine use of pneumococcal conjugate vaccine in the U.S. Disease rates fell not only among children, many of whom were unvaccinated, but also among adults. Protection of these unvaccinated groups likely occurred through decreased transmission of disease or “herd immunity.” This report provides important information that can be used for health economic evaluations of PCV, i.e. cost-effectiveness analyses.
What are the implications of these findings for cost-effectiveness analyses of PCV in the U.S.?
Initial cost-effectiveness estimates for PCV use in the U.S. only accounted for the benefits for vaccinated groups (direct effects). It would have been difficult to predict or quantify the benefits for unvaccinated groups (indirect effects or herd immunity) ahead of time, before routine immunization with PCV began. This study used multi-year surveillance data to estimate the indirect effect of PCV in the U.S. and showed that it is about double the direct effect. The size of the indirect effect we measured is probably larger than many experts would have predicted at the time the vaccine came into use. We hope the findings in this report will aid in analyzing the cost and health benefits of PCV more accurately.
What can countries that have not yet introduced pneumococcal vaccines learn from this U.S. experience?
What decision-makers can learn from the U.S experience is that PCV has the potential to make a significant public health impact, both through direct protective effects among immunized children and through herd immunity effects in other segments of the population. Although the magnitude of direct and indirect effects of PCV may differ by country, based on a variety of factors (such as the overall burden of severe pneumococcal disease and the distribution of the bacteria in the population), the U.S. experience shows that routine use of PCV can dramatically reduce severe pneumococcal disease.