STEVE INSKEEP, HOST:
Next, we have two reports on malaria. In the last decade, a lot of progress has been made to control that disease. But it still infects more than 200 million people per year, and kills around 650,000 - most of them, children. We'll look at why experts are worried about the emergence of a form of malaria in Southeast Asia, that's resistant to a commonly used drug. First, we have news about another way to control malaria - with a vaccine. NPR's Richard Knox has the latest on a study just out this morning, in the New England Journal of Medicine.
RICHARD KNOX, BYLINE: The public health world has been waiting for these results for over a year. The hope was the vaccine, tested in seven African countries, would be at least as effective in very young infants, as it proved to be in toddlers. But today's results are - well, disappointing. The vaccine reduced infants' risk of malaria by about a third. In contrast, the vaccine lowered the risk in toddlers by 50 percent, in a report released last October. But Dr. David Kaslow says a vaccine that protects only a third of infants, is enough to make a big difference.
DR. DAVID KASLOW: Malaria is so prevalent in these African kids. And so even a modest protection translates into large, public health impact. It will reduce disease, and it will save lives.
KNOX: Kaslow is director of a nonprofit called PATH Malaria Vaccine Initiative. It's funneled hundreds of millions of dollars into the vaccine study. Researcher John Lusingu helped test the vaccine in Tanzania.
JOHN LUSINGU: Being a father from sub-Saharan Africa, I have witnessed my own children suffering from several episodes of malaria.
KNOX: He's disappointed the vaccine didn't lower malaria by at least half, in infants. But he agrees with Kaslow that it could prevent high fevers, seizures, anemia and death, in a lot of African kids. Infants are considered the top priority group, partly because it was hoped malaria shots could be given to them along with other infant vaccines.
LUSINGU: So I would highly encourage that this vaccine should be incorporated into other, existing tools, to control malaria in sub-Saharan Africa.
KNOX: The question raised by the study is: How good does a malaria vaccine have to be, to justify its licensure in widespread use?
DR. MONCEF LAOUI: I think it is good enough.
KNOX: That's Dr. Moncef Laoui. He acknowledges he has a strong bias.
LAOUI: I have to tell you, I've been involved with the discovery of this vaccine from day one. I'm a co-inventor of this vaccine and therefore, I have a very strong passion, and commitment, to it.
KNOX: On top of that, Laoui is chief of research for the pharmaceutical giant GlaxoSmithKline, which has poured $300 million into developing and testing the vaccine. But he admits the new results are worse than expected.
LAOUI: I expect that the first reaction is one of a level of skepticism; a new level of disappointment with the number. I think part of that is, of course, real. Everybody would have hoped for that number to be higher.
KNOX: Still, it would be a mistake to write off the vaccine. Dr. Richard Feachem, of the University of California-San Francisco, says the best childhood vaccines are 90 percent protective; but the perfect shouldn't be the enemy of the good-enough.
DR. RICHARD FEACHEM: A clear failure is a clear failure, and a 90 percent efficacy is, you know, a glass of champagne. But this slides in the middle because there are so many uncertainties.
KNOX: Over the next couple of years, researchers will try to figure out why infants in this study didn't have a better immune response; and whether the vaccine performs better in places where malaria has been reduced by other means, such as insecticide-treated bed nets. Meanwhile, Feachem says the disappointing vaccine results increased the urgency to develop newer, better insecticides against malaria-infected mosquitoes; and new classes of drugs, to cure those who get infected.
Richard Knox, NPR News.