A new needle-free DNA vaccine against the Zika virus is being tested on people, US health officials have announced – moving forward in the fight against the virus that has been linked to serious birth defects. As a part of an early study run by the US National Institute of Allergy and Infectious Diseases (NIAID), about 80 volunteers in the US aged 18 to 35 will receive the NIAID Zika virus investigational DNA vaccine. If the vaccine appears safe and produces a good immune response against the virus, researchers plan to start a Phase 2 trial in 2017 in countries where Zika outbreaks are occurring, said Anthony Fauci, director of NIAID.
The vaccine contains a small, circular piece of DNA called a plasmid. Within that plasmid are genes that code for certain Zika virus proteins, ‘Live Science’ reported. These will cause an immune response against the virus, thus protecting from infection, the researchers said. This type of vaccine is known as a DNA vaccine, and researchers have used it in the past for diseases such as West Nile virus.
All the volunteers will get at least one dose of the vaccine, and some will get two or three doses that are spaced out over a number of weeks. The vaccine will be given with a needle-free “jet injector,” which uses a high-pressure stream of fluid to inject the vaccine into the muscle. Researchers will continue to follow the participants for two years to measure how long their immune response lasts, Fauci said.