The University of Vermont Vaccine Testing Center has announced that it will be involved in the development of a vaccine for Zika virus, which was declared a global health emergency by the World Health Organization on Feb. 1.
The Vermont Vaccine Testing Center has a long-standing partnership with the National Institutes of Health (NIH) lab that developed a dengue vaccine and is developing the Zika vaccine.
UVM’s test center and Center for Immunization Research at Johns Hopkins University in Baltimore will be test sites for the safety and immune response testing of an NIH-developed Zika vaccine candidate in humans. Because of the potential for a link of Zika infection with birth defects, pregnant women or those who may become pregnant will be excluded from Zika vaccine trials.
UVM faculty Kristen Pierce, M.D., an infectious disease specialist and associate professor of medicine, and Sean Diehl, Ph.D., an immunologist and assistant professor of medicine, have expertise in the characteristics of flaviviruses which are a group of viruses, mostly transmitted via insects, that cause such human diseases as Zika virus, yellow fever, dengue, various types of encephalitis, hepatitis C and related vaccines.
An infectious disease physician, Pierce, of Monkton, has led several dengue and West Nile virus vaccine-related trials. Diehl, of Shelburne, studies the basic mechanisms of flaviviruses, vaccines against flaviviruses, and the immune responses triggered by flavivirus natural infection or vaccination.
Pierce said about 80 percent of people who are infected with Zika are asymptomatic. The other 20 percent of people experience non-specific symptoms consisting of fever, rash, joint pains and sometimes an associated conjunctivitis. “Symptoms usually begin within a few days after a person has been bitten by an infected mosquito and last up to one week,” she said. “Symptoms are usually mild. Severe disease leading to hospitalization or death from Zika virus infection is quite rare.”
Mother-to-child transmission of Zika has been demonstrated throughout all stages of pregnancy, leading to fetal demise and possibly microcephaly, Pierce said. “There has been a significant increase in the number of cases of Brazilian children born with microcephaly since the start of the Zika virus outbreak. Studies are currently ongoing to determine whether there is a definite association between the increased incidence of microcephaly and Zika virus infection.”
Diehl said to prevent contracting Zika virus, avoid travel to countries where Zika is circulating. “Use insect spray containing DEET and wear clothing that fully covers the skin, utilize sleeping facilities with air conditioning and insect screens; bed nets can also be used, but Aedes aegypti and Aedes albopictus mosquitos are primarily daytime biters,” he said.