Dr. Joseph Lange may well have been on the cusp of ending HIV when his Malaysian Airlines flight was shot down by pro-Russian rebels in 2014. Dr. Seema Yasmin joins us to talk about Lange’s research into how the virus is transferred from mother to child – and about how his death has slowed progress towards a cure. Yasmin’s new book is called “The Impatient Dr. Lange: One Man’s Fight to End the Global HIV Epidemic” (Johns Hopkins University Press).