NIAID is developing multiple vaccine candidates to prevent Zika virus infection. These include:
- A DNA-based vaccine developed by scientists at NIAID’s Vaccine Research Center (VRC). The strategy is similar to the VRC’s investigational flavivirus vaccine for West Nile virus infection. The DNA-based Zika vaccine candidate entered a Phase 1 clinical trial at NIAID in August 2016. A second Phase 1 trial testing an optimized vaccine design launched in December 2016. Initial findings indicate the optimized vaccine is safe and able to induce a neutralizing antibody response against Zika virus. In March 2017, NIAID launched a Phase 2 clinical trial, which aims to enroll at least 2,490 healthy adult and adolescent participants in areas of confirmed or potential active mosquito-transmitted Zika infection. Sites are located in Houston, Puerto Rico, Brazil, Peru, Costa Rica, Panama and Mexico. Additional sites may be added in the future. The two-part trial, called VRC 705, further evaluates the safety and immunogenicity of the vaccine and will assess the optimal dose for administration. It also will attempt to determine if the vaccine can effectively prevent disease caused by Zika infection.
- A purified inactivated Zika vaccine called ZPIV, developed by the Walter Reed Army Institute of Research (WRAIR). ZPIV is based on a similar approach that WRAIR used to develop vaccines against the related Japanese Encephalitis and dengue viruses. Four of five Phase 1 trials testing ZPIV have begun at the Walter Reed Army Institute of Research (WRAIR) Clinical Trial Center in Silver Spring, Maryland; the Center for Vaccine Development at the Saint Louis University School of Medicine, the Center for Virology and Vaccine Research, part of Beth Israel Deaconess Medical Center and Harvard Medical School in Boston; and the clinical research center CAIMED, part of Ponce Health Sciences University in Puerto Rico. NIAID is co-funding the Phase 1 clinical trials program with WRAIR, serving as the regulatory sponsor for several of these clinical studies and providing other support. NIAID’s VRC will also test ZPIV as a boost to its DNA Zika vaccine candidate.
- A live-attenuated (in which the virus has been weakened so that it cannot cause disease) investigational vaccine designed to protect against disease caused by Zika virus and dengue virus infection. Scientists in NIAID’s Laboratory of Infectious Diseases developed the vaccine, which is closely related to a dengue vaccine candidate currently being evaluated in a large Phase 3 study in Brazil. A monovalent version of the vaccine that is designed to protect solely against Zika virus will enter a Phase 1 trial at Johns Hopkins University in Baltimore and University of Vermont. Another version of the vaccine designed to protect against Zika and all four types of dengue will enter clinical testing in early 2018. NIAID is working with Brazil’s Butantan Institute and the University of Sao Paolo to plan later-stage trials.
- Several investigational mRNA vaccines (a gene-based platform similar to DNA vaccines). NIAID’s VRC is working with GlaxoSmithKline (GSK), University of Pennsylvania and Moderna/Valera to evaluate various mRNA vaccine technologies to identify immunogenic and scalable candidates. The Moderna/Valera candidate is being evaluated in a Phase 1 trial, and the candidate developed by NIAID VRC and GSK could enter clinical trials in late 2017.
- An investigational Zika vaccine that uses a genetically engineered version of vesicular stomatitis virus—an animal virus that primarily affects cattle. VSV was successfully used in an investigational Ebola vaccine tested by NIAID. This vaccine approach is at an early stage with plans underway to evaluate the Zika vaccine candidate in tissue culture and animal models.
- A vaccine designed to protect against multiple mosquito-borne diseases, including Zika. The investigational vaccine, called AGS-v, was developed by the London-based pharmaceutical company SEEK, which has since formed a joint venture with hVIVO in London. AGS-v is designed to trigger an immune response to mosquito salivary proteins rather than to a specific virus or parasite carried by mosquitoes. The test vaccine contains four synthetic proteins from mosquito salivary glands. The proteins are designed to induce antibodies in a vaccinated individual and to cause a modified allergic response that can prevent infection when a person is bitten by a disease-carrying mosquito. The AGS-v candidate is being evaluated in a Phase 1 clinical trial at the NIH Clinical Center in Bethesda, Maryland.