Some progress has been made in the last decade, but there is currently no effective malaria vaccine on the market, according to the CDC. One obstacle is that malaria parasites have a complex life cycle, and there is poor understanding of the immune response to the infection. As of right now, there is only one vaccine - RTS,S – to show a protective effect against malaria among young children in a Phase 3 trial. Beginning in 2019, it will be the first provided to young children through routine immunization programs. Three sub-Saharan African countries will introduce the vaccine in selected areas as part of a large-scale pilot implementation program, the World Health Organization (WHO) says.