When I’ve traveled abroad, I’ve gotten my share of jabs for hepatitis and other diseases. But for malaria, the best I could hope for was to take malaria-blocking drugs like Lariam, which gave me weird dreams at night and made me feel as if someone was tugging my hair all day.

For people who live in countries with malaria, these prophylactic drugs just aren’t practical. Given that 800,000 people a year die of malaria, why don’t we have a good vaccine for it? It’s not for lack of trying–in fact, this year marks the 100th anniversary of the first attempts to make a malaria vaccine.

To understand this epic fail, I talked on my latest podcast with Irwin Sherman, a malaria expert and author of The Elusive Malaria Vaccine: Miracle or Mirage?.

Check it out.