Research will be conducted in the Preclinical Research Section of the Medical Countermeasures Department within the Viral Diseases Branch of the Walter Reed Army Institute of Research (WRAIR). The proposed research will focus on exploring mosquito factors with the potential to influence transmission, establishment of infection within the vertebrate, and/or pathogenesis of disease, with the overall goal of improving challenge models of medically important mosquito-borne viruses and/or improving vaccine platforms by targeting novel antigens. Potential projects could include: 1) determining titers and any associated variability of expectorated viruses during blood-feeding, 2) characterizing expectorated substances during mosquito blood-feeding, such as individual mosquito salivary proteins, 3) characterizing humoral and cellular immunity to expectorated substances in extant samples from ongoing cohort studies, 4) development of assays for surveillance of vector exposure.