Figure 1.

Hospitalized patients with confirmed influenza and vaccination status. (A) We report the number of cases of influenza at a single academic institution by week in non–intensive care unit (ICU) and ICU settings. (B) There was a high number of individuals that had not received the flu vaccine within 2 weeks of acute illness. There was a higher frequency of unvaccinated individuals in the ICU when compared with hospitalized non-ICU patients. (C) Similarly, there was a high number of individuals that had not received the flu vaccine who required positive pressure ventilation (PPV) (Optiflow [Fisher & Paykel, Auckland, New Zealand], bilevel positive airway pressure or conventional mechanical ventilation) for respiratory insufficiency, when compared with hospitalized patients who did not require ventilator support. Two-tailed Fisher exact test was used for statistical comparisons.