Should we worry about the most recent Omicron subvariants, BA 4 and BA5? They are the subtypes of the Covid-19 virus now dominant in southern Africa and spreading elsewhere. New research suggests that they are better at evading our antibody defences than other forms of the virus. Columbia University virologist David Ho explains the findings and what they means for us.

Also, reducing air pollution makes agricultural crops grow better, how large wildfires warm the upper atmosphere, and the dolphins in the Red Sea which use secretions from corals and sponges as preventative medicines.

Image Description: Coronavirus COVID-19 virus
Credit: Getty Images

Presenter: Roland Pease
Producer: Andrew Luck-Baker