Community-acquired pneumonia is a common condition resulting in considerable illness and death, according to background information in the article. A vaccine against Streptococcus pneumoniae, one of the causes of pneumonia—23-valent polysaccharide pneumococcal vaccine (PPV)—has been available since 1983. Most guidelines recommend PPV for those at high risk of developing pneumonia, including older adults and nursing home residents. However, some doubts have been raised about the effectiveness of PPV, and vaccination rates remain below the target 80 percent to 90 percent in these populations.
Jennie Johnstone, M.D., and colleagues at the University of Alberta, Edmonton, Canada, collected data on 3,415 patients with community-acquired pneumonia admitted to six hospitals between 2000 and 2002. The patients' vaccination status was determined through interviews, medical record reviews, contact with primary care physicians and records from the regional office of community health.
Of the patients, 22 percent had been vaccinated with PPV, and 624 died or were admitted to the intensive care unit (ICU). Those who had been vaccinated with PPV were less likely to die or be admitted to the ICU than those who had not been vaccinated (10 percent vs. 21 percent). This finding was mostly a result of lower ICU admissions—less than 1 percent of those vaccinated were admitted to the ICU, compared with 13 percent of those who were not vaccinated. Results were similar when the researchers looked only at patients older than 65 or those living in nursing homes—groups for whom universal PPV vaccination is recommended.
"In addition to improved clinical outcomes, our results suggest that there may also be an associated reduction in costs associated with pneumococcal vaccination, a health economic benefit that has not been captured in previous cost-effectiveness analyses of this vaccine," the authors write. "Specifically, much of the benefit in our study was in terms of reduction in the need for costly ICU admissions; previous cost analyses have been restricted to examining the benefits of preventing pneumococcal disease but may have not adequately captured the possibility of attenuating the severity or mitigating the cost of disease in those for whom pneumonia is not prevented."
Although 2,416 of the patients were eligible for vaccination upon being discharged from the hospital, only 215 (9 percent) received PPV at this time. "We believe that our results further the emphasize the importance of adopting current adult pneumococcal vaccination guidelines, particularly since only 22 percent of our population were vaccinated before their hospitalization and less than 10 percent of eligible patients were vaccinated before hospital discharge," the authors conclude.