Pneumococcal Disease

Health Professionals Overview

Widespread use of two vaccines-pneumococcal polysaccharide in adults and conjugate vaccine in children-has led to dramatic reductions in rates of invasive pneumococcal disease. Just four years after widespread vaccination of infants using the conjugate vaccine began, rates of invasive disease in infants declined 70 to 80 percent.[ABCs, Whitney] Herd immunity was also noted, evidenced by declining incidence in unvaccinated adults.

However, for those who get invasive pneumococcal disease, excess morbidity and mortality remains a considerable issue.[CDC 2006] Pneumococcal bacteremia is associated with a case-fatality rate of about 20 percent with rates as high as 60 percent in elderly patients. Pneumococcal meningitis is associated with similar mortality rates-30 percent overall and about 80 percent in the elderly.

The conjugate pneumococcal vaccine (PCV7) used in children contains seven pneumococcal strains that caused over 80 percent of invasive disease from 1978 to 1994 in children younger than 6 years.[CDC 2006a] The vaccine is part of the routine childhood immunization schedule, with primary doses administered at 2, 4 and 6 months and a booster dose at 12 to 15 months of age.[CDC 2005]

The polysaccharide vaccine (PPV23) contains 23 strains that cause 88 percent of invasive bacteremic disease in adults.[CDC 2006a] The vaccine should be administered routinely to all adults 65 years and older. The vaccine is also indicated for anyone 2 years or older with certain chronic illnesses.[CDC 2005]

In 2004, the PCV7 vaccine coverage rate in children 19 to 35 months of age was 73 percent [CDC 2006b] and the PPV23 vaccine coverage rates in persons 65 and older was 64. Given the severity of pneumococcal disease and the proven effect of the vaccines, increasing these vaccination rates would result in even more significant reductions in pneumococcal-related morbidity and mortality.

References

CDC. Active Bacterial Core surveillance (ABCs). Surveillance reports: streptococcus pneumoniae, 1997-2004. Available at: http://www.cdc.gov/ncidod/dbmd/abcs/reports.htm. Accessed March 9, 2006.

CDC. Epidemiology and Prevention of Vaccine-Preventable Diseases, The Pink Book. 9th ed., Jan. 2006a.

CDC. National Immunization Survey (NIS) data tables. Available at: http://www.cdc.gov/nip/coverage/NIS/04/toc-04.htm. Accessed March 9, 2006b.

CDC. Recommended childhood and adolescent immunization schedule - United States, 2006. MMWR 2005;54 (51&52):Q1-Q4.

Whitney CG, Farley MM, Hadler J, et al, for the Active Bacterial Core Surveillance of the Emerging Infections Program Network. Decline in invasive pneumococcal disease after the introduction of protein-polysaccharide conjugate vaccine. N Engl J Med 2003;348:1737-1746.

CDC. Behavioral Risk Factor Surveillance System (BRFSS). Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5145a3.htm. Accessed April 3, 2006.