Comparative effectiveness of individual pneumococcal vaccines with dual pneumococcal vaccination in older United States Veterans.

INTRODUCTION

Pneumococcal vaccination recommendations are constantly evolving. Recent pneumococcal vaccination guidelines have been updated to recommend pneumococcal conjugate vaccines in older adults. However, the clinical benefits of protein conjugate vaccine (PCV 13), pneumococcal polysaccharide vaccine (PPSV 23) and dual vaccination when compared to each other remain unclear.

METHODS

A retrospective cohort study conducted between 2014 and 2016 conducted at the Veterans Health administration (VHA) (N = 1,277,575). Primary outcomes were pneumococcal pneumonia and pneumococcal meningitis. Secondary outcomes were "other" pneumonia and "other" meningitis. "Other" referred to episodes of pneumonia and meningitis without an identified etiological agent.

RESULTS

PCV 13 was associated with decreased risk of pneumococcal pneumonia (Adjusted HR 0.69; 95 % CI 0.51 to 0.93) and "other" pneumonia (Adjusted HR 0.74; 95 % CI 0.64 to 0.86) when compared to PPSV 23. No significant difference was found between PCV 13 and PPSV 23 in terms of pneumococcal meningitis (Adjusted HR 3.98; 95 % CI 0.74 to 21.32; P = 0.12) and "other" meningitis (Adjusted HR 0.81; 95 % CI 0.33 to 2.03; P = 0.66). Dual vaccination was also associated with a decrease in the rate of pneumococcal pneumonia (Adjusted HR 0.88; 95 % CI 0.77 to 0.99; P = 0.03) and "other" pneumonia (Adjusted HR 0.90; 95 % CI 0.85 to 0.95; P < 0.01) in comparison to PPSV 23.

CONCLUSIONS

PCV 13 was associated with a 31% decrease in the rate of pneumococcal pneumonia in comparison to PPSV 23 in older adult Veterans. Our results demonstrating clinical benefit with PCV 13 vaccination are in alignment with the latest pneumococcal vaccination guidelines that recommend routine vaccination with pneumococcal conjugate vaccines in all older adults.