Identification of strain-specific nucleotide sequences in E1 and NS4 genes of rubella virus vaccine strains in Japan

Strain-specific nucleotide sequences of E1 and NS4 genes in five strains of a live rubella virus vaccine manufactured in Japan were identified for comparison, using 2389 nucleotides (1443 nucleotides of the EI gene, 41 of the 3' terminal region following the E1 gene and 905 of the NS4 gene). Sequences of the E1 gene in three strains (Matsuura, TCRB19 and To-336) were identified. Takahashi and Matsuba strains shared common sequences, but were discriminated by the sequence of the NS4 gene. These five strains showed a phylogenetic relationship with the places of their isolation. In a comparative study of three strains with their unattenuated progenitors, the nucleotides in these regions were almost conserved during the attenuation process. (C) 1997 Elsevier Science Ltd.