Needle-free jet injection of small doses of Japanese encephalitis DNA and inactivated vaccine mixture induces neutralizing antibodies in miniature pigs and protects against fetal death and mummification in pregnant sows.
Japanese encephalitis (JE) virus causes abortion and stillbirth in swine, and encephalitis in humans and horses. We have previously reported that immunogenicity of a DNA vaccine against JE was synergistically enhanced in mice by co-immunization with a commercial inactivated JE vaccine (JEVAX) under a needle-free injection system. Here, we found that this immunization strategy was also effective in miniature pigs. Because of the synergism, miniature pigs immunized twice with a mixture of 10 μg of DNA and a 1/100 dose of JEVAX developed a high neutralizing antibody titer (1:190 at 90% plaque reduction assay). Even using 1 μg of DNA, 3 of 4 pigs developed neutralizing antibodies. Following challenge, all miniature pigs with detectable neutralizing antibodies were protected against viremia. Pregnant sows inoculated with 10 or 1 μg of DNA mixed with JEVAX (1/100 dose) developed antibody titers of 1:40-1:320. Following challenge, fetal death and mummification were protected against in DNA/JEVAX-immunized sows.
Imoto
Jun-ichi
J
Department of International Health, Kobe University Graduate School of Health Sciences, Kobe, Japan.
Ishikawa
Tomohiro
T
Yamanaka
Atsushi
A
Konishi
Misako
M
Murakami
Kenji
K
Shibahara
Tomoyuki
T
Kubo
Masanori
M
Lim
Chang-Kweng
CK
Hamano
Masataka
M
Takasaki
Tomohiko
T
Kurane
Ichiro
I
Udagawa
Haruhide
H
Mukuta
Yoshihiro
Y
Konishi
Eiji
E
D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002522:Chlorocebus aethiops; D004664:Encephalitis Virus, Japanese / Q000276:immunology; D004672:Encephalitis, Japanese / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D005313:Fetal Death / Q000517:prevention & control / Q000662:veterinary; D007277:Injections, Jet; D007313:Insecta / Q000166:cytology; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D011247:Pregnancy; D013552:Swine; D013556:Swine, Miniature; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology; D014709:Vero Cells; D014766:Viremia / Q000276:immunology / Q000517:prevention & control
D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D022321:Japanese Encephalitis Vaccines; D019444:Vaccines, DNA; D015164:Vaccines, Inactivated