Figure 1. Peak Respiratory Severity of Adults Hospitalized With Respiratory Syncytial Virus (RSV), COVID-19, or Influenza by Vaccination Status.

Peak respiratory severity was classified by an ordinal scale as follows: (1) no oxygen therapy; (2) standard-flow oxygen therapy (<30 L/min); (3) high-flow nasal cannula (≥30 L/min) or noninvasive ventilation; (4) invasive mechanical ventilation; and (5) death.