The 7-valent pneumococcal conjugate vaccine (PCV7) was approved in 2000 to prevent pneumococcal disease in children younger than five years. The Centers for Disease Control and Prevention (CDC) has released results from a study evaluating the vaccine’s impact on invasive pneumococcal disease in children since its approval. The report, “Direct and Indirect Effects of Routine Vaccination of Children with 7-Valent Pneumococcal Conjugate Vaccine on Incidence of Invasive Pneumococcal Disease—United States, 1998–2003,” was published in the September 16, 2005, issue of Morbidity and Mortality Weekly Report and is available online athttp://www.cdc.gov/mmwr/preview/mmwrhtml/mm5436a1.htm.
The population-based study showed that the vaccine effectively prevented invasive pneumococcal disease in the targeted age group as well as in older children and adults; more than twice as many cases were prevented through indirect effects on the disease than through the direct protective effects of the vaccine. Increases in disease caused by serotypes not included in the vaccine were small compared with the overall decrease in vaccine-serotype disease. Ongoing surveillance is needed to confirm the effectiveness of PCV7.