Brand new results of a fourth Covid booster trial, with a mix and match approach including half doses, reveals good news for global vaccine rollout. BBC Health and Science correspondent James Gallagher explains.

Plus evidence from Ohio where Professor Ihuoma Eneli's new paper shows how weight gain increased markedly in low-income US children and teenagers during early Covid-19.

And the science of dreams, Claudia Hammond speaks to Brazilian neuroscientist Sidarta Ribeiro about his new wide ranging book The Oracle of Night.

Presenter: Claudia Hammond

(Picture: A patient who has received a fourth Covid-19 vaccination in Rieti, Italy. Photo credit: Riccardo Fabi/NurPhoto/Getty Images.)