Figure 2. Clinical Severity of Covid-19 as Indicated by Outcomes among Case Infants, According to Maternal Vaccination Status.

Critical Covid-19 was defined as Covid-19 leading to life-supporting interventions (i.e., noninvasive mechanical ventilation [bilevel positive airway pressure or continuous positive airway pressure], invasive mechanical ventilation, vasoactive infusions, or extracorporeal membrane oxygenation) or to death. An infant could have been included in more than one outcome category. Two infants who had been born to unvaccinated mothers (2 of 450 infants [<1%]) received extracorporeal membrane oxygenation. An additional 2 infants who had been born to unvaccinated mothers (2 of 442 infants [<1%]) died; among the 450 infants who had been born to unvaccinated mothers, 8 had mothers for whom data on hospital discharge were not available. ICU denotes intensive care unit.