An early-stage study to evaluate the safety and efficacy of an experimental Zika vaccine in humans is being launched by the National Institute of Allergy and Infectious Diseases (NIAID). “Results in animal testing have been very encouraging,” said NIAID Director Anthony Fauci, MD. “Although it will take some time before a vaccine against Zika is commercially available, the launch of this study is an important step forward.”
The NIAID scientists developed the investigational vaccine earlier this year. The approach is similar to that taken for another NIAID investigational vaccine developed for West Nile virus, which was found to be safe and effective in a phase 1 clinical trial. The vaccine includes a plasmid (small piece of DNA) engineered to contain genes that code for proteins of the Zika virus. The body reads the genes and makes Zika virus proteins, which cause an immune response. The DNA vaccines do not contain infectious material and cannot cause a vaccinated person to become infected with Zika.
The phase 1 clinical trial (VRC 319) will involve 4 groups of 20 people. The participants will be vaccinated at the first visit, and then half will receive another vaccination 8 weeks or 12 weeks later. The remaining participants will receive 2 additional vaccines, 1 group at week 4 and week 8; the other group, at week 4 and week 20. Participants will be followed for 44 weeks.
The study will be conducted at the NIH Clinical Center in Bethesda, the Center for Vaccine Development at the University of Maryland, and Emory University, Atlanta. Initial safety and immunogenicity data from the trial are expected by January 2017. In early 2017, If the results are favorable, NIAID plans a phase 2 trial in Zika-endemic countries.