Scott Halstead is an American physician-scientist, virologist and epidemiologist known for his work in the fields of tropical medicine and vaccine development.

He is considered one of the world's foremost authorities on viruses transmitted by mosquitoes, including Dengue, Japanese encephalitis, chikungunya and Zika.

[16][14] In 1991, Halstead was president of global health organization American Society of Tropical Medicine and Hygiene (ASTMH).

[17] In 1999, he began working at the Uniformed Services University of the Health Sciences in Bethesda, Maryland, and remained a consultant with the U.S.

PDVI was founded to promote and fund basic science and applied clinical research to accelerate the development of dengue vaccines.

After an analysis of Phase 3 clinical trial data, Sanofi scientists concluded that Halstead and Russell were correct and that Dengvaxia posed a significant risk for previously uninfected people.

In 2018, Halstead served as an expert witness, testifying in person at Philippines Senate hearings on what became known as the Dengvaxia controversy.

[21] During the global COVID-19 pandemic that started in 2019, Halstead began researching protecting at-risk groups via antibody-based strategies including convalescent plasma and monoclonal antibodies.