Mortality reductions for older adults differ by race/ethnicity and gender since the introduction of adult and pediatric pneumococcal vaccines.

OBJECTIVE

We determined the effectiveness of a 23-valent-polysaccharide pneumococcal vaccine (PPV-23) and pneumococcal conjugate vaccine (PCV-7) in reducing adult pneumococcal mortality by comparing historically predicted declines in pneumococcal disease mortality with observed patterns since the introduction of PPV-23 and PCV-7, including analyses of age, gender, and racial/ethnic subgroups.

METHODS

We analyzed all deaths registered on U.S. death certificates reporting any site of pneumococcal infection (e.g., meningitis, sepsis, pneumonia, bacteremia, and peritonitis) from 1968 to 2006. We used time-series dynamic linear regression on annual pneumococcal mortality rates to determine the percentage reduction in post-1983 mortality rates for a given increase in PPV-23 vaccination rates and post-2000 mortality rates for a given increase in PCV-7 vaccination rates.

RESULTS

Pneumococcal mortality decreased well before the introduction of PPV-23 in 1983 and again before the introduction of PCV-7 in 2000. The level of PPV-23 vaccination was associated with a direct and significant reduction in adult mortality, especially white female adults > or = 65 years of age. In contrast, the level of PCV-7 vaccination in the population was not associated with an indirect and significant reduction in pneumococcal mortality beyond the historical pace of decline.

CONCLUSIONS

PPV-23 introduction was associated with a reduction in pneumococcal mortality among older adults > or = 65 years of age beyond levels predicted by secular trends, whereas PCV-7 introduction was not. Mortality reduction was not uniformly experienced across the population, revealing the need for additional strategies to reduce pneumococcal mortality in older adults.