IMpact of pneumococcal conjugate vaccine in reducing overall exacerbation rate in COPD: results of the IMPROVE COPD study

Abstract

Background: Exacerbations triggered by infectious agents punctuate the course of COPD subjects and have a bearing on clinical outcomes. Pneumococcal vaccination brings down the occurrence of community-acquired pneumonia in COPD patients. The impact on exacerbation rate, although deemed to be beneficial, is less well elucidated. Objectives: To compare the differences in annual exacerbation rate, all-cause community-acquired pneumonia (CAP) occurrence, and all-cause hospitalisation in COPD patients prior to and after 13 valent pneumococcal conjugate vaccination (PCV 13). Methods: This was a 1-year study in pneumococcal vaccine naïve COPD patients who had at least one hospitalisation with acute exacerbation in the past year. Study subjects were vaccinated with the 13 valent pneumococcal conjugate vaccine during hospital stay. Patients were followed up for a period of 1 year after PCV 13 vaccination and the COPD exacerbation rate, occurrence of CAP, and all-cause hospitalisation were noted down. These parameters were compared in the year prior to vaccination and the year after vaccination. Results: Fifty-eight patients were included in the study. The mean annual exacerbation rate was 3.69 in the year prior to vaccination in comparison with 1.17 in the year after vaccination (P < 0.0001). Mean annual number of all-cause hospitalisation was 1.60 versus 0.71 in the year prior to and after PCV 13 administration (P < 0.0001). Eighteen episodes of CAP episodes occurred in the year prior to PCV 13 dosage as opposed to 7 in the subsequent year. Isolation of Streptococcus pneumoniae in CAP was made in 3 cases in the year before vaccine administration, whereas no S. pneumoniae isolate was obtained in the follow-up year after vaccination. Conclusions: Pneumococcal conjugate vaccination reduces the exacerbation rate in COPD patients who had prior hospitalisation with exacerbation. All-cause hospitalisation is also reduced after pneumococcal vaccination. The occurrence of CAP is decreased after PCV 13 administration.