LARGER BENEFIT OF 13-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV13) ON VACCINE PREVENTABLE DISEASE IN ADULTS (ID 625)
- Bradford D. Gessner, United States of America
- Jose A. Suaya, United States of America
- Michael W. Pride, United States of America
- Chris Webber, United States of America
- Raul Isturiz, United States of America
- Bradford D. Gessner, United States of America
Abstract
Background
In the Netherlands randomized controlled trial (RCT) of 13-valent pneumococcal conjugate vaccine (PCV13) among persons age 65+ years, the primary outcome was chest x-ray (CXR) confirmed, vaccine-type (VT) primarily non-bacteremic Community Acquired Pneumonia (CAP), the latter determined almost entirely by serotype-specific urinary antigen detection (SSUAD). The sensitivity and specificity of SSUAD and CXR for identifying primarily non-bacteremic pneumonia preventable by PCV13 is unknown.
Methods
In the Netherlands RCT, we compared vaccine-preventable-disease-incidence (VPDI) for all episodes of clinically defined CAP to that for CXR-confirmed VT-CAP. VPDI was calculated as the incidence rate difference between controls and vaccinated persons.
Results
VPDI per 100,000 person-years of follow-up for all episodes of clinical CAP vs. VT-CAP were: total population, 72.2/25.1 (2.9-fold); at-risk condition for pneumococcus other than immunosuppression, 121.4/34.3 (3.5-fold); and not at-risk, 35.5/17.6 (2.0-fold) (Table).
Conclusions
PCV13 prevented 2.0 to 3.5 more episodes of clinical CAP than CXR-confirmed VT-CAP, reflecting that SSUAD was designed for the regulatory outcome of vaccine efficacy, which relies on test specificity, and that CXR may have imperfect sensitivity for CAP in elderly persons. Assessing PCV13’s true public health value will require use of rate reductions or adjustment factors to account for clinically defined CAP.