Zika Update: U.S. Government Begins Human Trials of Zika Vaccine

The federal government will start human trials for a Zika vaccine, health officials said.

The National Institute of Allergy and Infectious Diseases (NIAID), a part of the National Institutes of Health (NIH), will be launching an investigational human trial of a Zika vaccine, in response to the increasing number of local transmission cases in the U.S.

The vaccine, which is called the NIAID Zika virus investigational DNA vaccine, was developed by NIAID's Vaccine Research Center (VRC) earlier this year.

"A safe and effective vaccine to prevent Zika virus infection and the devastating birth defects it causes is a public health imperative," Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said in a statement.

"NIAID worked expeditiously to ready a vaccine candidate, and results in animal testing have been very encouraging. We are pleased that we are now able to proceed with this initial study in people. 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 trial will take place in three locations in the U.S., including the NIH Clinical Center in Bethesda in Maryland, with at least 80 volunteers. The trial will test the safety of the vaccines and their ability to generate response from the immune system.

For the first phase of the trial, the volunteers will be divided into four study groups of 20 people each. All participants will receive a vaccination, shot under high pressure into the arm, and the groups will receive either one or two additional vaccinations after a few weeks. After the vaccination, the participants will remain in the clinic and will be observed by researchers 30 minutes. The participants will be given a diary card to use at home to record their temperature and any symptoms for a week following each vaccination.

The volunteers will also undergo follow-up visits to have their blood samples taken for laboratory testing to measure their immune response to the vaccine.

The results of the trial are expected to be available by January 2017. If the results are positive, the NIH will conduct another trial in countries where the Zika virus is spreading.

The NIAID had used the same approach in developing another investigational vaccine for the West Nile virus.

According to the NIH, there are over 6,000 Zika cases in the continental U.S. and territories. The mosquito-borne virus has already infected at least 14 people in Miami, Florida.