TABLE 3.

Comparison of neutralizing antibody titers using prototype JEV (Nakayama) and ChimeriVax-JEV in PRNT90

Specimen type (no. of samples)Specimen no.Neutralizing antibody titers in PRNT90a
Prototype JEV NakayamaChimeriVax-JEV
JEV vaccinated (55)11,2801,280
2640320
36401,280
4 and 5160160
6160320
716080
8 and 916040
10 and 118040
124040
134020
142020
15 and 1620
17-204010
21-261010
27-55
JEV infection (14)562,56020,480
575,12010,240
581,28010,240
592,5605,120
606405,120
616402,560
626401,280
63 and 643201,280
65 and 661601,280
67 and 68640640
69320320
Other flavivirus infections (21)
    DENV infection (9)70-78
    WNV infection (1)79
    YFV infection (3)80-82
    Past or secondary flavivirus infection (8)83320640
8410
85-90
All flavivirus negative (10)91-99
10020
Positive control—JEV vaccine serumb1,280320
Negative controlc
  • a The neutralizing antibody titer is expressed as the reciprocal of the endpoint serum dilution that neutralized the challenge virus plaque count by 90%. LLOQ has a neutralizing antibody titer of 10; only positive titers (≥10) are shown. Dash = no detectable titer (<10).

  • b MHIAF produced against JEV Nakayama strain.

  • c Normal human control serum.