Malaria is a leading cause of death and illness around the world. Over 200 million cases are reported every year, and more than 400 000 people die. More than 90% of cases are reported in sub-Saharan Africa. Scientists have spent decades searching for an effective vaccine. Hence the recent excitement when Malawi’s government announced it had launched a pilot programme for the world’s first malaria vaccine, RTS,S (also known as Mosquirix©), produced by the pharmaceutical company, GSK. It’s the first vaccine to demonstrate significant reduction in malaria in children. The Conversation Africa’s Ina Skosana asked immunologist Faith Osier about RTS,S.