| vaccinoprophylaxis of mumps using mumps vaccine, strain sofia 6, in bulgaria. | a mumps vaccine, using strain sofia 6 prepared in guinea-pig kidney primary cell cultures, was gradually introduced in bulgaria to vaccinate 1- to 12-year-old children between 1972 and 1976. it was included in the national vaccine programme in 1977. the vaccine showed a slight reactogenicity, a good immunogenicity and a high epidemiological efficacy. due to the increased morbidity of mumps, revaccination was carried out in 4- to 12-year-old children in 1982. a high level of side-effects, mainly ... | 1994 | 7856287 |