Giardia parasite breakthrough could lead to malaria vaccine

A Howard Hughes Medical Institute international research scholar has reported in the journal Nature Medicine that advances have been made in creating a vaccine against the intestinal parasite Giardia lamblia.

There are more than 200 protein coats in Giardia lamblia's molecular arsenal. The parasite, which causes diarrheal infections, can change the appearance of these protein coats to throw off the body's immune cells.

Hugo Lujan has reported that by engineering Giardia parasites to express all of their various surface proteins, the parasite work as a vaccine that can prevent or mitigate future infections.

The new method for creating the vaccine, which has yet to be tested in humans, has shown to protect gerbils infected with Giardia when given orally.

Lujan says that the breakthrough might aid in fighting more than just Giardia. He says that the surface-proteins may one day be used to fight other parasites, including malaria.

In most cases, surface proteins expressed by infectious pathogens are destroyed in the gastrointestinal tract long before the immune system has a chance to respond, Lujan said. But with the Giardia proteins, antigens might be able to survive in the gastrointestinal tract long enough for the immune system to recognize them.

"This could be a huge development," Lujan said, according to "Hopefully, we'll be able to use this system to make vaccinations that we can give in a very convenient way. Giardia's surface proteins are fascinating, and now we're finding that we can exploit what the parasite uses to defend itself to our own favor."