Characterization by T1-oligonucleotide fingerprinting of three strains of human hepatitis A virus isolated in Italy.

Three human hepatitis A virus strains, all of them isolated in Italy but one acquired abroad, were analyzed by T1-RNAase oligonucleotide mapping and by monoclonal antibody neutralization. The variation among their genomes according to T1-maps was calculated to be about 9%, thus confirming the poor genomic variation assessed by nucleotide sequencing (1-10%). However T1-maps of these Italian isolates were different from those reported in the literature (Weitz and Siegl, 1985). Neutralization by monoclonal antibody caused a reduction in titres of 2-25 log10. This genomic stability, if confirmed, is important with a view to a valuable vaccine.