Analyses of amino acid sequences in hypervariable region‐1 of hepatitis C virus (HCV) in sera from chimpanzees infected three times with the same HCV strain

BACKGROUND: To investigate whether or not the same strain of hepatitis C virus (HCV) can twice re-infect the same chimpanzee, we analyzed nucleic and amino acid sequences in HCV hypervariable region-1 (HVR1). Two chimpanzees were inoculated, three times each, with the same HCV strain during the 1983-1991. After each inoculation, chimpanzees developed acute hepatitis C, and then recovered. METHODS: Using sera, HVR1 cloning and antibody to HVR1 major clone measurement were performed. RESULTS: Clones from the first inoculum were divisible into major and minor types. Clones from the second and third inocula, as well as all post-inoculation sera, were essentially identical to the major type. Titers of antibody to HVR1 major clone were consistently low in pre- and post-inoculation sera. CONCLUSIONS: Both chimpanzees were re-infected twice with the same strain of HCV. The sequences from the second and third infections were similar to the major sequences in the first inoculum.