nurse hands holding syringe and ampoule

The first of five early stage clinical trials to test the safety and ability of a Zika vaccine candidate has begun in America.

The Zika Purified Inactivated Virus (ZPIV) vaccine, which is designed to generate an immune system response, is being tested at the Walter Reed Army Institute of Research (WRAIR) Clinical Trial Center in Silver Spring, Maryland.

Scientists with WRAIR, part of the US Department of Defense, developed the vaccine and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health is co-funding the Phase 1 clinical trial with WRAIR.

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.

NIAID Director Anthony S. Fauci, M.D. said: “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.”

Led by WRAIR principal investigator Maj. Leyi Lin, M.D., the new study aims to enroll 75 people ages 18 to 49 years with no prior flavivirus infection. Flaviviruses include Zika virus, yellow fever virus, dengue virus, Japanese encephalitis virus and West Nile virus.

A sub-group of 30 of the participants who receive the two-dose ZPIV regimen will receive a third dose one year later. All participants in the trial will receive the same ZPIV dose at each injection (5 micrograms).

Four additional Phase 1 studies to evaluate the ZPIV investigational vaccine are expected to launch in the coming months.