variant are on the rise. the big unanswered questions remain — what impact the variant will have on illness, vaccines and transmission. dominic hughes, bbc news. jenny harries is the chief executive of the uk health security agency. she says we're in a period of great uncertainty. almost all the public health professionals are very concerned about the variant, it has far more mutations than anything we have seen before and some of the characteristics of these mutations give us concern that it might start to evade either natural immunity where we have been infected before or the great efforts we have made with vaccination. but all of this is a period of great uncertainty and that is the key point. we are taking precautionary measures in order that we buy ourselves some time, so we can carry through the scientific tests we normally do to understand the variant better. the boss of iceland has said