Candid No. 1 Argentine hemorrhagic fever vaccine protects against lethal Junin virus challenge in rhesus macaques.

Abstract

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.

• Authors: K T McKee Jr, J G Oro, A I Kuehne, J A Spisso, B G Mahlandt
• Journal: Intervirology (Intervirology) Vol. 34 Issue 3 Pg. 154-63 ( 1992) ISSN: 0300-5526 [Print] Switzerland
• PMID: 1338783 (Publication Type: Journal Article)

Chemical References

• Antibodies, Viral
• Vaccines, Attenuated

Topics

• Animals
• Antibodies, Viral (blood)
• Arenaviruses, New World (immunology, isolation & purification, pathogenicity)
• Hemorrhagic Fever, American (immunology, prevention & control)
• Immunization Schedule
• Macaca mulatta
• Neutralization Tests
• Treatment Outcome
• Vaccination
• Vaccines, Attenuated (administration & dosage, immunology, therapeutic use)
• Viremia
• Virus Shedding