CD40LG and infection: Volunteers were classified into three different groups based on their serological profiles as follows: (i) group 1, presence of anti-CHIKV IgM suggesting recent or possible acute infection stage; (ii) group 2, presence of both IgM and IgG suggestive of a possible convalescent phase; and (iii) group 3, presence of anti-CHIKV IgG only, corresponding to past infection.