In addition to the three SARS-CoV-2 antigen specificities (Spike, RBD, and NC), B cells reactive to hemagglutinin (HA) from H1N1/pdm2009 influenza virus, fusion glycoprotein (F) from respiratory syncytial virus (RSV), or tetanus toxoid vaccine (TT) were evaluated to compare the composition of the specific B cell compartments early after infection (SARS-CoV-2) to those specific B cell compartments (Flu/RSV/TT) that were established longer ago. Here, CHMP5 is linked to infection.