Whereas all the current available vaccines produce humoral immune responses to SARS‐CoV‐2 S protein,[5, 6, 7] antibodies to N protein appears only due to infection, therefore, rapid point‐of‐care serological assays for SARS‐CoV‐2 N protein specific IgM and IgG antibodies can help differentiating between vaccinated, recovered and actively infected cases. This evidence concerns the gene CD40LG and infection.