The movie trailer above features clips from three episodes in Season 4 of HBO's acclaimed drama series Game of Thrones: "Mother's Mercy," "Eastwatch" and "Beyond the Wall." Click here for full reviews and detailed descriptions of each clip.Summary

Background Vaccination against measles, mumps, and rubella (MMR) vaccination has increased substantially since 1991 in England and Wales and Scotland and reduced MMR incidence among vaccinated individuals by 90%. Despite evidence that MMR vaccination confers protection against persistent infections