Candid No. 1 Argentine hemorrhagic fever vaccine protects against lethal Junin virus challenge in rhesus macaques.
The protective efficacy of Candid No. 1, a live-attenuated vaccine against Argentine hemorrhagic fever (AHF), was evaluated in non-human primates. Twenty rhesus macaques immunized 3 months previously with graded doses of Candid No. 1 (16-127, 000 PFU), as well as 4 placebo-inoculated controls, were challenged with 4.41 log10 PFU of virulent P3790 strain Junin virus. All controls developed severe clinical disease; 3 of 4 died. In contrast, all vaccinated animals were fully protected; none developed any signs of AHF during a 105-day follow-up period. Viremia and virus shedding were readily detected in all placebo-vaccinated controls, while virus could be recovered only once (by amplification) from throat swabs of 2 Candid No. 1 vaccinees on day 21. Vigorous secondary-type neutralizing and immunofluorescent antibody responses were seen in most vaccinees that had received 3 log10 PFU Candid No. 1 or fewer; all others, including those receiving 127,200 PFU, maintained relatively stable titers during follow-up. Candid No. 1 was highly immunogenic and fully protective against lethal Junin virus challenge in rhesus macaques, even at extremely low (16 PFU) vaccine doses.
McKee
K T
KT
United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Md.
Oro
J G
JG
Kuehne
A I
AI
Spisso
J A
JA
Mahlandt
B G
BG
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D006477:Arenaviruses, New World / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D006478:Hemorrhagic Fever, American / Q000276:immunology / Q000517:prevention & control*; D007115:Immunization Schedule; D008253:Macaca mulatta; D009500:Neutralization Tests; D016896:Treatment Outcome; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use*; D014766:Viremia; D017201:Virus Shedding
D000914:Antibodies, Viral; D014613:Vaccines, Attenuated