Scientists from Yale University have developed a serum that can reduce infection from malaria in mice. Their work was published in Cell Host & Microbe yesterday.
"It's a new general strategy for a vaccine. Rather than targeting the microbe, we target a mosquito protein that influences the environment where the microbe is transmitted," said Erol Fikrig, senior author of the study.
One question this group had was whether the mosquito saliva that is deposited with the malaria parasite (Plasmodium) played a role in the infection. To find the answer, Fikrig and the team developed a serum that could immunize against extracts of mosquito saliva. They then conducted screens to identify proteins in saliva that the serum recognized. After more experiments, they found that one protein that they called AgTRIO contributed to protection against malaria on its own.
The group was able to show that the serum could reduce the infection level in immunized mice that were bitten by mosquitos. They were even able to see this protective effect in other tests with different species of malaria parasites and human liver cells.
The serum could help boost the protective effect of currently malaria vaccines, which are about 40% effective against some severe forms of the disease. Fikrig notes that the serum would probably be most effective when associated with a traditional vaccine.
If the vaccine strategy proves to be safe and effective, it could have implications for other infections caused by mosquitos. "It's possible that this model could work with other mosquito-borne viruses, bacteria, or protozoa in this case," Fikrig said.