“…Epidemiological and serological studies have suggested the involvement of a number of different enveloped RNA viruses in MS, including measles virus (MV), canine distemper virus (CDV), simian virus 5 (SV5) and rubella virus (Haire et al, 1973;Norrby et al, 1974;Haire, 1977;Meurman et al, 1977;Cook et al, 1978;Goswami et al, 1987). Measles virus is still a prime candidate on the basis of evidence from serological studies of MS patients and controls (Adams & Imagawa, 1962;Haire et al, 1973 ;Norrby et al, 1974;Haire, 1977;Salmi et al, 1972Salmi et al, , 1983Felgenhauer et al, 1985) whereas data suggesting the involvement of SV5 or CDV are either not reproducible or are non-specific for the virus in question (Madden et al, 1981 ;Halle et aL, 1982;Brankin et al, 1989).…”