Level of neutralizing activity in serum samples obtained from patients with secondary acute dengue infection and from selected non acute dengue patients against each of the 4 DENV serotypes.

aInfecting serotype indicates the DENV serotype detected in the serum sample as determined by RT-PCR.bNeutralizing titers (PRNT50) to each of the 4 DENV serotypes for five DENV-1 patients and for two DENV-3 patients were less than 10 (PRNT50Table 3. Neutralizing antibody titer to 4 DENV serotypes were determined by a conventional PRNT method using FcγR-negative BHK cells and FcγR-expressing BHK cells as indicated in Materials and Methods.cNeutralizing antibody titers were determined for samples from selected non acute dengue patients.