Victories in the global fight against malaria are few and far between, so researchers cheered the news that a vaccine being tested in Africa protected children from the disease 30% of the time and lessened the severity of illness in nearly 60% of cases. The vaccine isn't ready for use yet, even if the world can ill afford to wait. The 300 million to 500 million malaria cases each year cause 1 million to 3 million deaths, most of them kids.