Omicron Covid variant – what do we know? Claudia examines key questions about the new variant with Professor of Molecular Virology, Jonathan Ball.

Plus growing evidence that pollution has a negative effect on our mental health. And a new way of testing for TB in children.

Presenter: Claudia Hammond
Producer: Erika Wright

(Image: Microscopic view of influenza virus cells. Photo credit: Panorama Images/Getty Images.)