Anti-spike antibody level is associated with the risk of clinical progression among subjects hospitalized with COVID-19 pneumonia: results from a retrospective cohort study.

Purpose: Antibodies against SARS-CoV-2 spike (anti-S) may confer protection against symptomatic COVID-19. Whether their level predicts progression among those with COVID-19 pneumonia remains unclear.

Methods: We conducted a retrospective cohort study to assess predictors of anti-S levels and whether anti-S titer is associated with death or mechanical ventilation (MV).