Long-term antibody titers variation in unvaccinated patients receiving convalescent plasma or placebo for severe SARS-CoV-2 pulmonary infection.

Background: Convalescent plasma (CP) became a prominent treatment in the early stages of the SARS-CoV-2 pandemic. In Argentina, a randomized clinical trial was executed to compare the use of CP in inpatients with severe COVID-19 pneumonia versus placebo. No differences in clinical outcomes or overall mortality between groups were observed.