Testing of Inactivated Zika Vaccine in Humans Begins

The first of 5 early stage clinical trials to test the safety and ability of an investigational Zika vaccine candidate called the Zika purified inactivated virus (ZPIV) vaccine to generate an immune system response has begun at Walter Reed Army Institute of Research clinical trial center in Silver Spring. Scientists with WRAIR developed the vaccine. 

The experimental ZPIV vaccine is based on the same technology WRAIR used in 2009 to successfully develop a vaccine for another flavivirus called Japanese encephalitis. The ZPIV vaccine contains whole Zika virus particles that have been inactivated, meaning that the virus cannot replicate and cause disease in humans. However, the protein shell of the inactivated virus remains intact so it can be recognized by the immune system and evoke an immune response. 

NIAID partially supported the preclinical development of the ZPIV vaccine candidate, including safety testing and non-human primate studies that found that the vaccine induced antibodies that neutralized the virus and protected the animals from disease when they were challenged with Zika virus. 

“We urgently need a safe and effective vaccine to protect people from Zika virus infection as the virus continues to spread and cause serious public health consequences, particularly for pregnant women and their babies,” said NIAID director Dr. Anthony Fauci.