Studies conducted early in the COVID-19 pandemic reported that seroconversion occurs in approximately 90%–95% of SARS-CoV-2–infected adults, with SARS-CoV-2–specific IgM, IgG, and IgA antibodies detectable in most individuals within 2 weeks of symptom onset (2, 4, 30–34). The gene discussed is CD40LG; the disease is COVID-19.