Adjusted odds ratios for hospitalization and death by prior and current influenza immunization status.

Note. CI = confidence interval. 2003–04 could not contribute to pre-influenza period for hospitalizations and was excluded from all periods for mortality owing to early start to influenza season that year.aAdjusted for age, prior pneumococcal immunization, and medical visits prior year.bPneumonia, influenza, or acute respiratory disease listed as most responsible admission diagnosis.