CD40LG and infection: However, serology testing can reveal if there's an acute infection via three antibodies [24]: (1) viral capsid antigen (VCA) IgM antibodies, which indicate early infection stages and last four to six weeks; (2) VCA IgG antibodies, which peak two weeks after acute infection, then drop and persist for life; (3) anti-EB nuclear antigen (EBNA), which indicates previous infection and is usually detected after two to four months, persisting for life.