Cutting mosquito sugar is key to malaria vaccine

Blocking plasmodium parasites’ access to a natural sugar found in mosquitoes’ intestines decreases the spread of malaria, according to researchers at Johns Hopkins Malaria Research Institute.

Chondroitin sulfate, a sugar produced within mosquitoes, allows malaria-carrying parasites to feed and develop by attaching themselves to the stomach or guts of the insect.

By limiting the amount of these sugars within mosquitoes, studies show a decline in these parasites.

Previous studies were conducted on malaria-infected patients, but these findings make it possible to develop a vaccine.

“The parasite can’t spread by itself. It needs a host first. This vaccine will block the transmission of malaria even if you are bitten by a mosquito,” said Dr. Rhoel R. Dignlasan, Malaria Research Institute postdoctoral fellow and lead author of the study appearing Monday in the online Proceedings of the National Academy of Sciences.

When vaccinated individuals are bitten by mosquitoes, the insect becomes vaccinated as well, said Dignlasan, who is originally from the Philippines and lost a high school friend to malaria.

Malaria spreads through hosts, and this approach would result in a significant drop in new infections.

Each year, more than 1 million people die from malaria in sub-Saharan Africa.

These victims are primarily children, according to the Centers for Disease Control and Prevention.

There are similarities between these sugars in humans and mosquitoes, allowing for a mutual vaccination, Dignlasan said. “It appears as if the parasite’s use of sugars as a strategy for cell invasion of tissues is similar in both men and mosquito. This may be an Achilles’ heel for the parasite.”

Antibodies introduced to the mosquitoes’ guts provided a protective blanket against the parasite.

The study showed similarities between the sugars in humans and mosquitoes. Eliminating the sugar blocks the life cycle of 95 percent of the parasites.

lduffy@baltimoreexaminer.com