Protection of Aotus monkeys by Plasmodium falciparum EBA-175 region II DNA prime-protein boost immunization regimen.
Aotus monkeys received 4 doses of Plasmodium falciparum EBA-175 region II vaccine as plasmid DNA (Dv-Dv) or recombinant protein in adjuvant (Pv-Pv) or as 3 doses of DNA and 1 dose of protein (Dv-Pv). After 3 doses, antibody titers were approximately 10(4) in DNA-immunized monkeys and 10(6) in protein-immunized monkeys. A fourth dose did not significantly boost antibody responses in the Dv-Dv only or Pv-Pv only groups, but titers were boosted to approximately 10(6) in monkeys in the Dv-Pv group. Four weeks after the last immunization, the animals were challenged with 10(4) P. falciparum-parasitized erythrocytes. Peak levels of parasitemia were lower in the 16 monkeys that received region II-containing plasmids or proteins than in the 16 controls (geometric mean: 194,178 and 410,110 parasites/microL, respectively; P=.013, Student's t test). Three of 4 monkeys in the Dv-Pv group did not require treatment. These data demonstrate that immunization with EBA-175 region II induces a significant antiparasite effect in vivo.
Jones
T R
TR
Malaria Program, Naval Medical Research Center, Silver Spring, MD 20910, USA. jonest@nmrc.navy.mil
Narum
D L
DL
Gozalo
A S
AS
Aguiar
J
J
Fuhrmann
S R
SR
Liang
H
H
Haynes
J D
JD
Moch
J K
JK
Lucas
C
C
Luu
T
T
Magill
A J
AJ
Hoffman
S L
SL
Sim
B K
BK
D000276:Adjuvants, Immunologic; D000740:Anemia; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan; D001029:Aotus trivirgatus; D002352:Carrier Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D017780:Malaria Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016778:Malaria, Falciparum / Q000469:parasitology / Q000517:prevention & control*; D008297:Male; D018512:Parasitemia / Q000469:parasitology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014611:Vaccination; D019444:Vaccines, DNA / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology
D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D002352:Carrier Proteins; D017780:Malaria Vaccines; D015800:Protozoan Proteins; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; C065668:erythrocyte-binding antigen 175, Plasmodium