Long-term immunogenicity of the new Vero cell-derived, inactivated Japanese encephalitis virus vaccine IC51 Six and 12 month results of a multicenter follow-up phase 3 study.
Japanese encephalitis (JE) is the most common viral encephalitis in Asia. IC51 is a new Vero cell-derived, inactivated JE virus vaccine with non-inferior immunogenicity (after 2 months) compared to the US-licensed vaccine JE-VAX (mouse brain-derived, inactivated) and with a more convenient (two injections instead of three) intramuscular dose schedule. Adult subjects from two studies were followed-up for comparative immunogenicity (JE-VAX) at 6 months and long-term immunogenicity of IC51 alone at 12 months. At 6 months, immunogenicity was higher with IC51 (seroconversion rate [SCR] 95%; geometric mean titer [GMT] 84) than with JE-VAX (SCR 74%; GMT 34). At 12 months, the SCR was 83% and the GMT (41) remained above the protective titer of 1:10. Most people immunized with IC51 will have protective neutralizing antibody levels for at least a year.
Schuller
E
E
Intercell AG, Campus Vienna Biocenter 6, 1030 Vienna, Austria.
Jilma
B
B
Voicu
V
V
Golor
G
G
Kollaritsch
H
H
Kaltenböck
A
A
Klade
C
C
Tauber
E
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001208:Asia; D002522:Chlorocebus aethiops; D004311:Double-Blind Method; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D022321:Japanese Encephalitis Vaccines / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D013997:Time Factors; D015164:Vaccines, Inactivated / Q000276:immunology; D014709:Vero Cells
D000914:Antibodies, Viral; D022321:Japanese Encephalitis Vaccines; D015164:Vaccines, Inactivated