CD40LG and COVID-19: The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, led to more than 7 million deaths globally.1 Once a person is infected, the production of immunoglobulin (Ig) M, IgG3, IgG1 and IgA antibodies to the viral envelope (E), nucleocapsid (N) and spike (S) proteins are initiated.2,3 After infection, IgM and IgA appear around five days, followed by IgG at approximately 14 days.2,4,5,6 Studies suggest that IgG can be detected up to 12 months post SARS-CoV-2 infection.7,8