During the last few decades, vector-borne diseases have resurged dramatically. Several millions of new cases occur each year with devastating impacts on human and animal lives and economies. According to the World Health Organization, about 10% of the total global burden of diseases is due to those transmitted by arthropod vectors. Dr. Molaei’s research activities and interests are in the areas of vector-borne diseases with emphasis on the vector-host interactions as an essential element in transmission. He makes use of molecular biology techniques to better understand epidemiology and ecology of West Nile and eastern equine encephalitis viruses with the goal of reducing the risk of infections in humans and domesticated animals. Dr. Molaei’s research has revealed that while some mosquito vectors exhibit opportunistic blood feeding behavior, others show a great deal of specialization for feeding on only one group of vertebrate hosts. For some species, information is limited to a few locations that may be the reflection of host abundance rather than the innate preference. Clearly, the complexity of the vector-host interactions and its epidemiological relevance require further investigations.