CD40LG and dengue disease: A recent study of the validity of the serological diagnosis of dengue immunoglobulin G (IgG) and immunoglobulin M (IgM) by ELISA according to WHO recommendations [3] in acute febrile and in convalescent individuals vaccinated and unvaccinated (Placebo), and virologically confirmed or not, showed a high sensitivity (97.1%) but a low specificity (85.1%) in the IgM ELISA due to the presence of residual IgM from previous vaccination or subclinical undetected dengue, which may introduce a diagnostic bias [4].