First Anti-obesity Vaccine Shows Promise

Keith Haffer, Braasch Biotech LLC, South Dakota, developed the vaccines -- derived from a peptide hormone somatostatin -- in two versions, JH17 and JH18, and tested them in two groups of diet-induced obese male mice. A control group of mice was given a saline solution injection.

Somatostatin inhibits the action of growth hormone (GH) and insulin-like growth factor (IGF1), both of which increase metabolism and result in weight loss.

The two different formulations of the vaccine were designed to reduce production of the somatostatin in mice that had become obese after they were routinely fed high-fat chow. The formulations did not differ in their bioengineered active ingredient but in the "adjuvant" that was added to stoke the body's response to the vaccine. Both formulations showed a marked effect: compared with obese mice which did not get the vaccine, the weight gain of those who got either formulation slowed even though all the mice continued to get the same high-fat diet.

Four days after the first injection of modified somatostatin, the vaccinated mice had a 10 percent drop in body weight (not seen in the mice receiving saline shots), said a university statement.

By the end of the study, the weight gain of vaccine-treated mice was a much smaller proportion of overall body weight than it was for those that got a sham infusion. Compared with the control group, the mice that got either vaccine formulation had notably higher levels of a hormone called "growth factor" and more modest increases in IGF-1.

Later results showed that both vaccines induced antibodies to somatostatin and significantly reduced body weight, sustaining the lower body weight, without affecting normal levels of GH, IGF1, or insulin levels.

"This study demonstrates the possibility of treating obesity with vaccination," Haffer -explained. "Treatment of human obesity with vaccination would provide physicians with a drug and surgical free option against the weight epidemic."

Whether either will be safe, effective and cheap enough for use by millions of obese Americans will the subject of many future trials. Haffer said that obese dogs and pigs could be next in line for testing with the experimental vaccine.

Journal of Animal Science and Biotechnology, July 2012