Prior pneumococcal vaccination reduces mortality in elderly patients with community-acquired pneumonia: Study

"Prior pneumococcal vaccination resulted in higher in-hospital improvement (97.6% vs. 95.0%) and lower 30-day mortality rates (2.6% vs. 5.3%) versus the unvaccinated group," the researchers reported.

Further analyses confirmed a significant reduction in in-hospital mortality (HR 0.53) and 30-day mortality (HR 0.58) among the vaccinated.

Community-acquired pneumonia (CAP) remains a significant cause of morbidity and mortality, particularly among the elderly population. However, recent research suggests that prior pneumococcal vaccination could significantly reduce the risk of in-hospital mortality for these vulnerable individuals. However, there is a lack of real-world data on the efficacy of the pneumococcal vaccine in reducing mortality, especially in elderly patients.

To fill this knowledge gap, Jeong Uk Lim, The Catholic University of Korea, Seoul, Korea, and colleagues aimed to assess the effects of prior pneumococcal vaccination in elderly pneumonia patients.

For this purpose, the researchers procured data from the Health Insurance Review and Assessment and Quality Assessment database. It included hospitalized patients who met the community-acquired pneumonia criteria and were grouped according to vaccination state. Patients were aged ≥ 65 years and treated with quinolone, beta-lactam, or macrolide. Patients were excluded when treatment outcomes were unknown.

The researchers evaluated a total of 4515 patients, and 35.6% of them were vaccinated before hospitalization. The mean age was 77.0, 54.2% were male, and the mean Charlson comorbidity index (CCI) was 3.0.

The study led to the following findings:

• The patients in the vaccinated group were younger than those in the unvaccinated group (76.0 vs. 78.0 years) and showed higher in-hospital improvement (97.6 vs. 95.0%) and lower 30-day mortality (2.6 vs. 5.3%).
• After adjusting confounding factors such as age, gender, CURB score, and CCI score, the vaccinated group demonstrated a significant reduction in 30-day mortality (hazard ratio [HR] 0.58) and in-hospital mortality (HR 0.53) compared to the unvaccinated group in multivariate analysis.
• The vaccinated group showed better 30-day survival than those in the non-vaccinated group (log-rank test < 0.05).

In conclusion, the study showed the effectiveness of prior pneumococcal vaccination in elderly populations for improving in-hospital and 30-day mortalities among those hospitalized for pneumonia, however, it does not affect the length of admission duration.

"Emphasizing the importance of vaccination as part of comprehensive pneumonia prevention efforts could lead to improved outcomes and reduced healthcare costs associated with CAP in this vulnerable population," the researchers wrote.

Reference:

Kim, S., Kim, M.J., Myong, JP. et al. Prior pneumococcal vaccination improves in-hospital mortality among the elderly population hospitalized due to community-acquired pneumonia. BMC Pulm Med 24, 168 (2024). https://doi.org/10.1186/s12890-024-02928-8