Dengue virus type 1 DNA vaccine induces protective immune responses in rhesus macaques.
A candidate DNA vaccine expressing dengue virus type 1 pre-membrane and envelope proteins was used to immunize rhesus macaques. Monkeys were immunized intramuscularly (i.m.) or intradermally (i.d.) by three or four 1 mg doses of vaccine, respectively. Monkeys that were inoculated i.m. seroconverted more quickly and had higher antibody levels than those that were inoculated i.d. The sera exhibited virus-neutralizing activity, which declined over time. Four of the eight i.m.-inoculated monkeys were protected completely from developing viraemia when challenged 4 months after the last dose with homologous dengue virus. The other four monkeys had reduced viraemia compared with the control immunized monkeys. The i.d. -inoculated monkeys showed no reduction in viraemia when challenged with the virus. All vaccinated monkeys showed an anamnestic antibody response, indicating that they had established immunological memory. Vaccine-induced antibody had an avidity index similar to that of antibody induced by virus infection; however, no clear correlation was apparent between antibody avidity and virus neutralization titres.
Raviprakash
K
K
Virology Program, Infectious Diseases Department, Naval Medical Research Center, 503 Robert Grant Avenue, Rm 3N71, Silver Spring, MD 20910-7500, USA. ravik@nmripo.nmri.nnmc.navy.mil
Porter
K R
KR
Kochel
T J
TJ
Ewing
D
D
Simmons
M
M
Phillips
I
I
Murphy
G S
GS
Weiss
W R
WR
Hayes
C G
CG
D000818:Animals; D000915:Antibody Affinity; D003716:Dengue Virus / Q000276:immunology*; D007114:Immunization; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D008253:Macaca mulatta; D013601:T-Lymphocytes / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D019444:Vaccines, DNA; D014765:Viral Vaccines