By Robert Bazell

Among the infectious horrors facing humanity, malaria stands at or near the top. That’s why the somewhat positive results of a large clinical of a malaria vaccine may seem at first like excellent news. Unfortunately, it is not so simple.

First malaria vaccine works in major trial

The trial of the vaccine called RTS,S/AS01 enrolled 15,460 children in 11 African countries ages 6 to 12 weeks and ages 7 to 17 months. The results reported Tuesday describe the outcome from the first 6,000 children after 14 months. Put simply, after a year, about one-third of the kids who had the vaccine got sick, compared to one half of those given a placebo.

With malaria causing more than three-quarters of a million deaths a year in African children and making 250 million people a year sick -- often with terrible lasting consequences such as liver and kidney damage  --  why not just give the vaccine, even with its limits? After all, in some flu seasons and in some populations, flu vaccine is no more effective, yet the U.S. government pushes hard for all Americans to be immunized against influenza.

The problem with the malaria vaccine is that its limited effectiveness could devour resources better spent on interventions like mosquito netting that provide protection and faster access to care that saves lives and prevents complications from the disease. A malaria vaccine could also create a sense of security among both the affected population and public health officials -- making a terrible situation even worse.  The parasite that causes malaria mutates rapidly –- just like the flu virus -- and the results do not yet predict how long the immunity will last, or how well the vaccine will work in the future.

There will be, with the best of intentions, an enormous push to use the vaccine. Since 1987 the drug company GlaxoSmithKline has spent a fortune developing it and the Gates Foundation and other charities have generously helped fund the trials. Everyone who thinks about the malaria problem wants a vaccine. But a half-effective one is not the answer.

Robert Bazell is NBC's Chief Science and Medical Correspondent.