Safety and Immunogenicity of a First-in-Human Mosquito Saliva Peptide Vaccine

Overview

Background: Mosquitos carry diseases that cause major health problems and death worldwide. The AGS-v vaccine targets proteins in mosquito saliva. This may help prevent many mosquito-borne diseases. It might also reduce the lifespan of the mosquito that bites the vaccinated person. Objective: To see if the AGS-v vaccine is safe in humans and how it affects the immune system. Eligibility: Healthy adults ages 18-50 Design: Participants will be screened another study. Participants will be randomly assigned to get either the vaccine with a booster vaccine, the vaccine without the booster, or a placebo. These are given through a needle in the upper arm. Participants will have visits that include medical history, physical exam, and blood and urine tests: Baseline: They will get the vaccine and be monitored for 2 hours. Follow-up visits 1 and 2 weeks after baseline. Visit 3 weeks after baseline: They will get the booster and be monitored for 2 hours. Follow-up visits 1 and 2 weeks after booster visit. Visit 3-5 weeks after booster visit: This includes mosquito feeding. Mosquitos grown in the lab will be allowed to bite the arm. Blood will be drawn 4 times in the 3 hours after the feeding. Phone follow-up a few days after the mosquito feeding. After the feeding visit, 5 follow-up visits about every 2 months Participants will keep a symptom diary for 7 days after each vaccine. They will record their temperature. They will measure any redness around the injection site. They will document and if possible photograph any mosquito bites they get.

Mosquito-borne diseases continue to cause significant morbidity and mortality worldwide despite on-going control efforts. In 2015, there were \>200 million cases of malaria worldwide, causing nearly half a million deaths, with most of the deaths occurring among children under the age of 5 years. Mosquitos also transmit arboviruses, including dengue, yellow fever, West Nile virus, chikungunya, Rift Valley fever, Japanese encephalitis, and Zika virus. The current new outbreak of Zika virus in Central and South America, as well as the Caribbean, serves as a reminder of how quickly these viruses can spread and how difficult they can be to control. In this protocol we plan to perform a Phase I study of a novel universal mosquito-borne disease vaccine. Through modulation of the immune system after a mosquito feeding, this vaccine targets the vector saliva and may provide prophylaxis against multiple arboviral and protozoal diseases. In addition the vaccine potentially leads to a reduced mosquito lifespan after feeding therefore also reducing transmission of these diseases. In this protocol we hope to demonstrate the safety of this vaccine similar to SEEK s other peptide based vaccines Flu-v and HIV-v that have been found to have very good safety profiles in previous Phase I trials. We also hope to demonstrate immunomodulation after a controlled clean Aedes aegypti mosquito feeding to demonstrate proof of concept efficacy of the vaccine. With the current rise of Zika in the Americas and the threat of local mosquito transmission in the U.S. and the rest of the world, a successful universal mosquito-borne disease vaccine offers the benefit of targeting this emerging disease as well as the many established infections such as dengue and malaria that make dealing with this newly emerging epidemic a challenge.