Press Releases: Northern California
May 18, 2004
7-Valent pneumococcal vaccine decreases serious illness even in unvaccinated
Penicillin resistance to pneumococcal diseases also drops
OAKLAND, Calif. – Kaiser Permanente researchers are presenting the results of four years' study of Prevnar, a pneumococcal vaccine effective against seven types of pneumococcal disease, at the Society for Pediatric Research conference in San Francisco May 3rd.
Drs. Henry Shinefield and Steve Black followed Kaiser Permanente patients from before children received the vaccine in 2000 up to March 2004.
Their data show that even unvaccinated adults and older children are experiencing lower rates of pneumococcal disease since the vaccine's introduction. Reduction of invasive pneumococcal disease was 52 percent in children aged five to 19; 46 percent in people aged 20 to 39; 23 percent in those 40 to 59; and 32 percent for adults 60 and over.
"We're excited by these findings," says Dr. Shinefield. "Truly, this is an effect we hadn't expected—that the vaccine would reduce the rate of disease even in people who hadn't gotten it. It's clear that vaccinating children diminishes the circulation of the pneumococcus in the environment, prevents serious bacterial disease in infants and toddlers, and protects the rest of the population as well."
The study also found that since the vaccine's introduction penicillin-resistant pneumococcal infection has dropped from a high of 15 percent of all cases in 2000 to 5 percent in 2003.
"The decrease in penicillin resistance is related to the decrease in the community of the seven penicillin-resistant pneumococcal types present in the vaccine," says Dr. Shinefield.
Pneumococcus can cause pneumonia, meningitis and bacteremia—an infection of the bloodstream—in children and adults. The fatality rate of these diseases can go as high as 50 percent among adults. Immuno-compromised adults and smokers carry higher risks of contracting the diseases. (See the CDC's Web site> for more information.)
In Kaiser Permanente's study, funded by the manufacturers of the vaccine, Wyeth Inc., 37,868 children were vaccinated at two, four and six months, with a booster at 12 to 15 months. The randomized controlled trial, completed in 1999, looked at incidences of invasive pneumococcal disease, and at otitis media (ear infections) and pneumonia. The current report highlights the striking reduction of invasive pneumococcal disease in approximately 150,000 vaccinated and unvaccinated children under 5 years of age, as well the effects of the vaccine on the entire Kaiser Permanente Northern California population of over 3 million.
Kaiser Permanente is America's leading integrated health plan. Founded in 1945, it is a nonprofit, group practice prepayment health plan with headquarters in Oakland, California. Kaiser Permanente serves the health care needs of over 8.3 million members in 9 states and the District of Columbia. Kaiser Permanente has research centers in 8 regions around the United States and publication of KP investigators' work has appeared in the Journal of the American Medical Association, the New England Journal of Medicine, Pediatrics, the American Journal of Preventive Medicine, and other peer-reviewed medical journals.
Nationwide, Kaiser Permanente includes approximately 134,000 technical, administrative and clerical employees and 11,000 physicians representing all specialties.
