BMI: Body mass index; CAP: Community-acquired pneumonia; Cl: Confidence interval; PPSV23: 23-valent pneumococcal polysaccharide vaccine; PSI: Pneumonia severity index; VE: Vaccine effectiveness; VT: Vaccine-type (ie, 13-valent pneumococcal conjugate vaccine [PCV13]-type).
^*VE was calculated as 1 minus the odds ratio from the logistic regression model of PCV13 vs. no PCV13 multiplied by I00%. Season of enrolment was modeled as spring vs. summer vs. fall vs. winter. Age group was modeled as age 65 to 79 vs. ≥80 years. Gender was modeled as male vs. female. Race was modeled as white vs. non-white. Ethnicity was modeled as Hispanic vs. non-Hispanic. Place of residence was modeled as home vs. other. Risk level was based on Centers for Disease Control and Prevention classifications of risk for pneumococcal disease and modeled as healthy vs. at-risk vs. high-risk. BMI kg/m² was modeled as obese vs. overweight vs. normal weight vs. underweight; 2 patients were missing information about BMI and were excluded from the univariate and fully-adjusted models. PSI was modeled as a continuous variable; 1 patient was missing information about PSI and was excluded from the univariate and fully-adjusted models. Healthcare exposure in last 3 months, weekly exposure to children aged <5 years, influenza vaccine receipt within previous year, and history of PPSV23 in last 5 years were modeled as yes vs. no. One patient was missing information about weekly exposure to children aged <5 years and was excluded from the univariate and fully-adjusted models.

^†The crude model served as the final model because no evidence of confounding was observed in univariate or multivariable modeling.
^‡The fully adjusted model was simultaneously adjusted for all covariates listed in the table.