On the other hand, 41.5 % (n = 166/400) of the participants previously experienced symptoms similar to COVID-19, and among them there were anti-SARS-CoV-2 IgM-negative and IgG-negative cases at a prevalence of 59.0% (n = 98/166) and 34.3% (n = 57/166), respectively (p < 0.05). The gene discussed is CD40LG; the disease is COVID-19.