COVID-19-naïve individuals with PAD syndromes had reduced percentages of IgG1+ memory B cells relative to healthy donors at day 7 to 28 post-vaccination, with these individuals also displaying an elevated percentage of IgM+ SARS-CoV-2-specific memory B cells (Figures 3B, C; S4B, C). The gene discussed is CD40LG; the disease is COVID-19.