sentences:  After the start of the mass MMR immunisation programme, additional evidence that the strain was linked with viral meningitis surfaced in a number of countries, and by 1990, many had withdrawn products containing it.In November 1992, it was withdrawn in the UK, following the publication of government-sponsored research which confirmed a high incidence of transitory mild meningitis.Since that time, government agencies have acted to prevent the importation of single vaccines containing this strain.