Matrix protein gene sequence of vaccine and vaccine-associated strains of mumps virus.

Mumps virus is a member of the paramyxovirus group. The genome is negative-sense, linear ssRNA, consisting of 15384 nucleotides (nt). The mumps virus genome contains information for seven genes (3' N P M F SH-HN-L 5'). The protein products of six of the seven genes have been characterized and their estimated M r values determined. They are the nucleocapsid protein (N; 3//,. 70K), the phosphoprotein (P; M,. 45K), the matrix protein (M ; M r 39K), the fusion protein (F; Mr 69K), the haemagglutinin-neuraminidase protein (HN; M r 80K) and the large protein (L; M r 200K) (for review see Wolinsky & Server, 1985). Two non-structural proteins (M r 23K and 17K) (Rima et al., 1980) which are believed to be translated from the P gene mRNA by nucleotide editing (Elliott et al., 1990) are also present in infected cells. The nature of the SH gene products, if any, is not yet known. Mumps, measles and rubella (MMR) vaccine containing the live attenuated Jeryl Lynn or the Urabe strain of mumps virus is given to 1-year-old children in most European countries. Initial reports (Hockin & Furesz, 1988) indicated that one in about 100000 recipients developed aseptic meningitis after MMR vaccination containing the Urabe strain although recent estimates give a higher figure (Colville & Pugh, 1992). These symptoms are not observed with the MMR containing the Jeryl Lynn strain (Nalin, 1989, 1992) which has recently been shown to contain a mixed virus population (Afzal et al., 1992, 1993a). At present, the reasons for vaccine-associated adverse effects are not known.