Vaccinations have begun in a multi-site Phase 2/2b clinical trial testing an experimental DNA vaccine designed to protect against disease caused by Zika infection. The vaccine was developed by government scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). NIAID is leading the trial, which aims to enroll at least 2,490 healthy participants in areas of confirmed or potential active mosquito-transmitted Zika infection, including the continental United States and Puerto Rico, Brazil, Peru, Costa Rica, Panama and Mexico.
The two-part trial, called VRC 705, further evaluates the vaccine’s safety and ability to stimulate an immune response in participants, and assesses the optimal dose for administration. It also will attempt to determine if the vaccine can effectively prevent disease caused by Zika infection.
Most people with Zika infection have either no or only mild symptoms, such as fever, rash, joint pain and conjunctivitis (red eyes). However, when Zika infection occurs during pregnancy, the pregnant woman can pass the virus to her fetus, which can result in a range of fetal defects known collectively as congenital Zika syndrome. Currently there is no licensed vaccine to prevent disease caused by Zika infection, which is mainly transmitted via the bite of infected Aedes aegypti mosquitoes but also can be transmitted sexually.
“We are pleased to have advanced rapidly one of NIAID’s experimental Zika vaccines into this next stage of testing in volunteers. We expect this study will yield valuable insight into the vaccine’s safety and ability to prevent disease caused by Zika infection,” said NIAID Director Anthony S. Fauci, M.D. “A safe and effective Zika vaccine is urgently needed to prevent the often-devastating birth defects that can result from Zika virus infection during pregnancy. Evidence also is accumulating that Zika can cause a variety of health problems in adults as well. This trial marks a significant milestone in our efforts to develop countermeasures for a pandemic in progress.”