Figure 4. SARS-CoV-2-neutralizing Ab in human milk is maintained for at least 9 months after infection.

A proxy neutralization assay that measures Abs specific for the Spike receptor binding domain (RBD) that block the RBD-ACE2 interaction was performed using a premade kit according to instructions (Genscript). Dotted line: background neutralization level of COVID-19-naïve milk. Paired t-test was used for analysis. PI: post-infection.