Immune response to vaccination against Argentine hemorrhagic Fever in an area where different arenaviruses coexist.

Neutralizing antibody (NT Ab) titers to Candid #1 (C#1) vaccine against Argentine hemorrhagic fever were studied for 2 years post-vaccination in 330 volunteers, to assess whether the kinetics and/or magnitude of this immune response is modified by previous infection with the arena viruses Junin (JUN) and lymphocytic choriomeningitis (LCM). A total of 160 volunteers received C#1, distributed as follows: without detectable pre-infection with arenaviruses (n = 54); with pre-existing antibodies to JUN (n = 55); with pre-existing antibodies to LCM (n = 51). The remaining 170 individuals received placebo.

[Preclinical assay of candid #1 vaccine against Argentine Hemorrhagic Fever made in Argentina].

Candid #1 vaccine against Argentine Hemorrhagic Fever produced in USA versus lots of the same vaccine made in Argentina were compared in guinea pigs regarding safety, immunogenicity and protective efficacy against a challenge with pathogenic Junin virus. Lots No Exp 3, 7A and 8A of Argentine origin as well as lot TSI 5-1-92 from USA were inoculated in guinea pigs of 250-400 g in two consecutive assays. Ten animals inoculated with saline performed as normal controls in each experiment.

Evaluation of an enzyme-linked immunosorbent assay for detection of antibodies to Junin virus in rodents.

Junin virus is the etiological agent of Argentine hemorrhagic fever, a serious rodent-borne disease. An enzyme-linked immunosorbent assay (ELISA) to detect Junin virus IgG antibodies in rodents was evaluated using sera from 27 Calomys musculinus and five Calomys laucha, inoculated experimentally with a live attenuated strain of this arenavirus. The test performance was compared against an indirect immunofluorescence assay (IFA).