Nucleotide Sequence Analysis of the Hemagglutinin-Neuraminidase Gene of Urabe AM-9 Strain

Lee, Joo Yeon; Kim, Jee Hee; Lee, Jin Soo; Park, Ji Ho; Sohn, Young Mo

Abstract

PURPOSE
Urabe AM-9 strain was known to be associated with increased aseptic meningitis. The reason for high incidence of vaccine-associated meningitis was known that nucleotide(nt) substituted form G to A at position 1081 of the hemagglutinin-neuraminidase(HN) gene and therefore, glutamic acid changed to lysine at amino acid 335. We assessed by comparing nt sequence of the HN gene form Urabe AM-9 strain with wild strain and documented the correlation between nt substitution and vaccine-associated meningitis.
METHODS
Two lots of Urabe AM-9 vaccine distributed in Korea and mumps wild strains isolated from 1998 through 1999 were analysed. Analysis was made by nt sequencing following amplification of HN gene by RT-PCR.
RESULTS
Nucleotide substitution at position 343, 1476, 1570 was not found in both Urabe AM-9 vaccines and wild strains. But analysis of vaccine strains and wild strains isolated from patients revealed substitution from G to A at nt 1081 of the HN gene. Therefore, it encodes lysine instead of glutamic acid at amino acid 335. There was no mixture from of G and A at nt 1081. Nt at 1470 of one lot of Urabe AM-9 vaccines changed from C to A after Vero cell passage. Nt at 1727 of vaccines and wild strains was substituted A to G, so it encodes glycine instead of aspartic acid.
CONCLUSION
Nucleotide analysis of HN gene revealed that nt 1081 of Urabe AM-9 vaccines and wild strains had wild type AAA(Lys(335)) instead of variant type GAA(Glu(335)). The results of this study suggest that there was a probability of vaccine-associated meningitis due to Urabe AM-9 in Korea before. But incidence of actual side effect was not evaluated because there was no reporting system in Korea.