these new variants have been spreading fast in a number of different countries. 0ur science correspondent rebecca morelle has been looking at why they are such a threat and how to deal with future mutations as they come along. a year into the pandemic, and the virus is changing. new variants are emerging around the world, altering its structure and the waythe virus behaves. the variant spelling in the uk has a significant mutation. it's called n601y and it changes the spike of the virus. that spike is like a key opening up a lock. it inserts into receptors and enters ourselves. the mutation gives this key a much better fit, mutation gives this key a much betterfit, which is how it can infect more people. the variant in south africa and a separate one in brazil has another worrying mutation. it's called ea84k01y and