 Welcome back to NewsHour. Some good news for you now. Scientists at the University of Oxford say they've come up with a new malaria vaccine that is 80% effective in children and could be a game changer. Malaria kills more than half a million people a year, most of them small children. And millions more suffer the mosquito-borne disease every year, which has a huge impact on households and national economies. My colleague Rebecca Kesby has been speaking to lead researcher Professor Adrian Hill.