Omicron Covid variant – what do we know?

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.)