An all-in-one mosquito-borne diseases vaccine? NIH is testing a candidate

One thing that Zika, malaria, West Nile fever and dengue have in common is that they’re all spread by mosquitoes, and now the NIH has launched a phase 1 trial to test a vaccine that aims to fight them all.

The candidate, dubbed AGS-v, was developed by London-based pharma company SEEK. Instead of targeting each mosquito-borne diseases’ pathogen in separate vaccines, it is designed to trigger an immune response against mosquito saliva.

AGS-v consists of four synthetic proteins from mosquito salivary glands. In vaccinated subjects, it's intended to trigger a modified allergic response to prevent infections.

Mosquitoes cause the most human diseases among all animals. In 2015, malaria alone caused 438,000 deaths, according to the World Health Organization. Given the diseases' wide impact, Anthony Fauci, M.D., director of NIH’s National Institute of Allergy and Infectious Diseases, said in a statement that the new approach has the potential to become "a monumental public health advance."

NIAID plans to enroll up to 60 healthy adults ages 18 to 50 years for the trial. Randomly assigned groups of participants will receive different regimens: One group will get two injections of the AGS-v vaccine 21 days apart, another group two injections of AGS-v combined with an adjuvant with the same interval, and the rest two placebo injections.

Then, the participants will be exposed to biting mosquitoes with no viruses or parasites, and will return according to a preset schedule for researchers to monitor antibodies in their blood samples until about 10 months after the mosquito feeding.

Scientists are conducting the trial at NIH’s clinical center in Bethesda, Maryland, and expect to complete this round by next summer.

A lot of companies, including Big Pharmas, are working on vaccines targeting specific mosquito-borne diseases. Sanofi, which already has Dengvaxia for dengue fever, for example, is also working with the U.S. Army’s Walter Reed and Brazil’s Fiocruz on a Zika vaccine candidate.

Maryland-based Sanaria is moving quickly with its malaria vaccine candidate PfSPZ, catching up with GlaxoSmithKline’s Mosquirix. Japan’s Takeda, Austria’s Themis and California-based PaxVax are all in a tight race of getting the first Chikungunya vaccine to the market.