A single-dose of LcED III is able to induce cross-neutralizing antibodies and memory neutralizing antibodies.

<p>BALB/c mice (n = 5) were immunized once subcutaneously with 1, 5, or 20 µg of LcED III. (A) Seroconversion rates and (B) the optical density of serum samples at a 2500-fold dilution versus time after immunization are plotted. (C) Sera samples were collected four weeks after the immunization. The neutralizing antibody titer of the sera in each mouse was determined by FRNT. (D) Immunized mice were challenged intraperitoneally with 5×10⁶ FFU of live dengue-2 virus at week 28 post-priming. Sera obtained from naïve mice inoculated with live dengue-2 virus served as controls. Serum samples were collected in each mouse to evaluate neutralization of the infectivity of dengue virus by FRNT. The neutralizing antibody titer was calculated as the reciprocal of the highest dilution that resulted in a 40% reduction of FFU compared to that of a control that consisted of treatment with virus and pre-immunization sera.