What's the Latest Development?

In a recent study in Portugal, laboratory mice that were given a new "obesity vaccine", which blocks the appetite-stimulating hormone ghrelin, ate less and burned more calories than control mice which were not given the vaccine. "To develop the vaccine, Dr. Mariana Monteiro and her colleagues attached ghrelin to harmless, viruslike particles. The idea is that once injected, the body's immune system will develop antibodies against ghrelin, suppressing the hunger-causing hormone. Obese mice ate 50 percent less food after receiving the vaccine than mice who did not receive the vaccine."

What's the Big Idea?

What would such a vaccine mean for humans? "[The vaccine] would have advantages over current weight-loss drugs, which have side effects and cannot be used over the long term, said study researcher Dr. Monteiro, an associate professor at the University of Porto in Portugal. For example, the drug Merida was withdrawn from the market last year because of concerns it could increase heart attack and stroke risks. [The vaccine used in the study] appears to be safe so far, and its effects on the mice may last for years, the researchers said."