A Vaccine Against Giardia?

Giardia, scourge of backpackers everywhere, your reign of terror may soon be over. Scientists at the Catholic University of Córdoba in Argentina have made an exciting discovery that could yield a vaccine against giardia, a water-borne parasite that causes horrific bouts of diarrhea, vomiting, and flatulence when contracted by humans.

Giarda is especially difficult for human immune systems to vanquish because it constantly changes the coating of proteins that surrounds it. As soon as our antibodies recognize this protein and begin killing it, the next generation switches to a sheath made from one of the 190 other proteins at its disposal. Our antibodies then fail to identify this bastard protozoan, and we’re stuck with the Hershey squirts for a few more days.

But the Argentine scientists—can we go ahead and call them saints?—figured out how to force giardia to display all 190 protein coats at the same time. Then, when a vaccine is made from this altered protozoan, our bodies can immunize themselves to all 190 coats all at once. Our antibodies will see through all giardia’s disguises and eliminate them from our system before the protozoan can cause any adverse effects.

Tests in animals have yielded positive results, and vaccines for humans could be just on the horizon. But it’ll do more than make your camping trip easier: According to the World Health Organization, over 280 million people contract giardia a year, mostly in developing countries. They often suffer less crippling effects than westerners, but persistent giardia could be a cause of malnutrition.

Look out, giardia: We’re taking the water back.

—Ted Alvarez

A Coat of Many Proteins May Be Giardia’s Downfall (NY Times)

Via Get Outdoors GoBlog