Cholera Vaccine Challenge Study
The University of Vermont Vaccine Testing Center (UVM VTC) conducted a clinical trial of a single-dose, oral vaccine against cholera. In 2017, the groundbreaking vaccine, named Vaxchora, was approved by the U.S. Food and Drug Administration for use in the U.S.
Cholera is an acute diarrheal illness whose symptoms include diarrhea, vomiting, and dehydration, caused by ingesting contaminated food and water. Annually, there are an estimated 100,000 deaths and 3-5 million cases worldwide, although most cases are asymptomatic or mild. Cholera is a disease of poverty, occurring most commonly in countries where access to proper water sanitation is limited. Cholera in the United States is rare, though travelers to endemic areas are at risk if they consume contaminated food or water. Often, cholera cases can be treated with oral rehydration, but more severe cases require intravenous fluid replacement and antibiotics, and untreated cholera can cause death. The approval of Vaxchora represent the first time that a vaccine has been for individuals from the United States traveling to areas where cholera is present.
Campylobacter jejuni Infection Model
Campylobacter jejuni, a Gram-negative bacteria, is a top cause of food-borne disease in the United States and a common cause of diarrhea in young children globally. It is uniquely associated with post-infectious sequelae, including reactive arthritis, irritable bowel syndrome and, via molecular-mimicry, ascending paralysis (the Guillain-Barré syndrome). Our lab is working to improve serodiagnostic tests for the detection of Campylobacter jejuni infections and to better understand the cellular immune responses to this infection.
Typhoid Fever Vaccine Study
Salmonella typhi is another gram-negative bacterium that causes a severe febrile illness and is spread through contaminated food and water. The infection spreads in the host via invasion of host macrophages, using a type-III secretion system (TTSS). Despite vaccines against typhoid fever having been used for more than 100 years, typhoid fever still infects 15-30 million persons annually, killing 600,000. While the clinical arm of the VTC has worked with biotech partners to develop new typhoid vaccines, the laboratory focused on understanding correlates of immune risk to S. typhi infection and evaluating the functional immunology of candidate vaccines.