Covid: Who are the scientists hunting variants down in Wales?
Meet Jess Hey, a Public Health Wales scientist who is working on hunting down new variants of Covid-19.
She is part of a team of 16, based in Cardiff, that has been able to sequence between 15 to 20% of all positive cases in Wales since Covid arrived, one of the highest rates anywhere in the world.
Ms Hey, who only started three months ago, prepares samples selected at random from positive Covid tests across and helps to look for tiny differences between the samples in the virus's genetic code.
She said her work is "very different" from when she was a zoology student but "exciting".
A Covid variant, first spotted in Kent in the autumn, spread quickly and is now the dominant form across Wales and much of the UK.