CD40LG and infection: As enhancement of DENV infection has been associated with binding cross-reactive antibodies in the absence of detectable nAb activity, we assessed the levels of envelope binding IgM and IgG at 1, 4, and 7 days after DENV-2 infection using whole virus-based ELISA assays to determine if bAb levels unlike nAb were boosted immediately after infection (Fig. 4a–b).