title: Immune response to vaccination against Argentine hemorrhagic Fever in an area where different arenaviruses coexist.
abstract: 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. Levels of anti-JUN NT Ab displayed a trend in which titers increased with the virulence of the infecting strain, from C#1 (X = 49), through subclinical JUN infection (X = 229), vaccination following subclinical infection (X = 367) to JUN clinical infection (X =773). It was also found that the mean titer of NT Ab to C#1 did not vary significantly during 2 years of study and was: a) significantly lower than that elicited by wild strains of JUN, both clinical and subclinical infections (p < 0.01); b) significantly increased the titers of pre-existing anti-JUN Ab (p < 0.01); and c) was not modified by pre-existing anti-LCM Ab (p > 0.05). These data indicate that the immune response to C#1 boosts pre-existing immunity to JUN virus and is not changed by previous experience with LCM virus.
authors.affiliation: Instituto Nacional de Enfermedades Virales Humanas Dr JI Maiztegui, Parmagino, Argentina. anaambrosio@yahoo.com.ar
authors.forename: Ana M
authors.initials: AM
authors.lastname: Ambrosio
authors.forename: Laura M
authors.initials: LM
authors.lastname: Riera
authors.forename: María Del Carmen
authors.initials: Mdel C
authors.lastname: Saavedra
authors.forename: Marta S
authors.initials: MS
authors.lastname: Sabattini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D001117:Arenaviridae Infections / Q000276:immunology* / Q000821:virology; D006477:Arenaviruses, New World / Q000276:immunology*; D006478:Hemorrhagic Fever, American / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D006801:Humans; D018051:Junin virus / Q000276:immunology; D008216:Lymphocytic Choriomeningitis / Q000276:immunology* / Q000821:virology; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests; D016896:Treatment Outcome; D014611:Vaccination; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines