Pneumococcus is a common bacterium that can cause relatively minor illnesses such as
middle ear infection
as well as more serious illnesses such as
. In March 2000, a vaccine that protects against seven varieties of pneumococcus bacteria (PCV-7) was made available for infants and young children. Vaccinated children are less likely to spread the bacteria to other children and adults.
But has the PCV-7 vaccine actually decreased the occurrence of pneumococcal infections in adults? In an article published in the October 26, 2005
Journal of the American Medical Association
, researchers report that cases of pneumococcal disease have decreased significantly among adults aged 50 years and older in the years since children started routinely receiving the PCV-7 vaccine.
About the Study
The researchers analyzed data collected by the US Centers for Disease Control and Prevention (CDC) Emerging Infections Program on 4,978,000 adults, aged 50 years and older living in eight states. They noted all cases of invasive pneumococcal disease (meningitis, pneumonia, and bacteremia) that the CDC’s program diagnosed in these men and women from 1998 to 2003.
The incidence of invasive pneumococcal disease caused by the seven varieties of pneumococcus bacteria covered by the PCV-7 vaccine declined 55% from 22.4 cases per 100,000 adults in 1998-1999 (before the vaccine was introduced) to 10.2 cases per 100,000 adults in 2002-2003 (after the vaccine was introduced). This was a significant decline.
One limitation of this study was that the percentage of children immunized with the PCV-7 vaccine varied considerably.
How Does This Affect You?
This study found that the incidence of invasive pneumococcal disease declined significantly in older adults in the years after the PCV-7 vaccine was introduced to children in the community.
Usually when a child brings an illness home from daycare or school, it’s nothing more than a bothersome cold. But the possibility always exists that they’ll bring home something more serious. The PCV-7 vaccine protects children from pneumococcal infection, but it also reduces the likelihood that an immunized child will transmit a pneumococcal infection to another child or adult in the community.
As with any truly successful vaccine program, even unvaccinated members of a community stand to benefit, a concept parents ought to bear in mind when immunizing their own children. PCV-7 and other universal vaccine programs are not just good for children, but for the entire community.
National Immunization Program US Centers for Disease Control and Prevention www.cdc.gov/nip/
National Institute of Allergy and Infectious Diseases National Institutes of Health www3.niaid.nih.gov/
Lexau CA et al. Changing epidemiology of invasive pneumococcal disease among older adults in the era of pediatric pneumococcal conjugate vaccine.
. 2005; 294:2043-2051.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a