Low anti‐SARS‐CoV‐2 S antibody levels predict increased mortality and dissemination of viral components in the blood of critical COVID‐19 patients

Background Anti‐SARS‐CoV‐2 S antibodies prevent viral replication. Critically ill COVID‐19 patients show viral material in plasma, associated with a dysregulated host response. If these antibodies influence survival and viral dissemination in ICU‐COVID patients is unknown. Patients/Methods We studied the impact of anti‐SARS‐CoV‐2 S antibodies levels on survival, viral RNA‐load in plasma, and N‐antigenaemia in 92 COVID‐19 patients over ICU admission. Results Frequency of N‐antigenaemia was >2.5‐fold higher in absence of antibodies. Antibodies correlated inversely with viral RNA‐load in plasma, representing a protective factor against mortality (Adjusted HR [CI 95%], p): (S IgM [AUC ≥ 60]: 0.44 [0.22; 0.88], 0.020); (S IgG [AUC ≥ 237]: 0.31 [0.16; 0.61]