The National Institute of Allergy and Infectious Disease of the National Institutes of Health (NIH) awarded more than $2 million to a research team at the George Washington University (GW) School of Medicine and Health Sciences (SMHS) to facilitate a Zika vaccine trial in Brazil.
Zika is a mosquito-borne illness associated with the rainy season in Brazil. The world became widely aware of the virus and its methods of transmission in 2016 when an epidemic spread rapidly throughout South and Central America and cases were reported by travelers returning from this region to the United States. Since the outbreak, new Zika outbreaks have even been reported in Asia.
The research team led by David Diemert, MD, associate professor of microbiology, immunology, and tropical medicine at SMHS and Jeffrey Bethony, PhD, professor of microbiology, immunology, and tropical medicine at SMHS, is partnering with the Hospital das Clínicas and the Fundação Oswaldo Cruz in Belo Horizonte, Brazil to enroll 100 subjects into the clinical trial. In total, the trial will include 2,400 subjects across sites in Central and South America, Puerto Rico, and the southern United States. During the study, transmission of the virus will be monitored and additional volunteers may be signed up at sites with higher rates of infection.
"We are going into what is expected to be the transmission season in Brazil," explained Diemert. "That's one of the reasons we are heading into this trial now. The people in these areas will be vaccinated before we would start to see cases of Zika."
Over the course of the trial, researchers will focus on evaluating the safety and tolerability of the vaccine, as well as the efficacy of the vaccine compared to placebo. The vaccine being tested by the GW team was developed by the NIH.
The vaccine is a DNA vaccine, a vaccine that aims to elicit a strong antibody response using a microbe's genetic material. The DNA vaccine can be given to pregnant women. In contrast, a vaccine containing a live virus could pose a risk to the fetus if administered during pregnancy.
"The main concern about Zika virus infection is Congenital Zika Syndrome," Bethony said. "Some people will get Zika and are asymptomatic. However, infection in a woman who is expecting could put the child at risk for microcephaly."
Subjects who receive the injections will then be followed for a two-year period.
Following the trial, if the vaccine is determined successful, the populations in these endemic areas will see the potential for better prevention against infection with the Zika virus.