As the first place in the continental United States with a confirmed outbreak of Zika spread by mosquitoes last summer, Miami was announced this week as one of three sites where federal health officials will begin the second phase of a clinical trial testing an experimental DNA vaccine for the virus.
The vaccine was developed by federal government scientists with the National Institute of Allergy and Infectious Diseases, which is part of the National Institutes of Health. The trial will enroll at least 2,490 healthy participants in areas with confirmed or potential active spread of Zika by mosquitoes, including Miami, Houston, Puerto Rico, Brazil, Peru, Costa Rica, Panama and Mexico.
In South Florida, the clinical trial will take place at the University of Miami Miller School of Medicine, with Margaret Fischl, a UM infectious disease physician and scientist as the principal investigator responsible for conducting daily reviews of safety data. It will start next week.
The two-part clinical trial, called VRC 705, will investigate three areas: the vaccine’s safety in humans; its ability to stimulate an effective immune response; and the optimal dose and injection sites for usage. The trial also will help determine if the vaccine can effectively prevent transmission of Zika.
The vaccine candidate began early-stage human testing in 2016 after testing in animals, with the NIH reporting that initial findings indicate the vaccine is safe and able to induce a neutralizing antibody response against Zika.
The first part of the clinical trial will enroll 90 healthy men and non-pregnant women ages 18 to 35 in Houston, Miami and San Juan, Puerto Rico. All participants will receive the vaccine candidate during three separate visits that are four weeks apart.
Participants will be randomly assigned to receive either a standard dose or a high dose of the trial vaccine during all three visits, and will be followed for about 32 weeks.
The second part of the trial will enroll at least 2,400 healthy men and non-pregnant women ages 15 to 35 with the aim of determining whether the vaccine can protect against Zika. Sites will include Houston, Miami and San Juan, as well as Costa Rica, Peru, Brazil, Panama and Mexico.
Participants in the second part will be randomly assigned to receive either the trial vaccine or a placebo during three separate visits that are four weeks apart. Neither the scientists nor the participants will know who received the trial vaccine.
Part-two participants will be followed for nearly two years. Investigators will compare the rates of confirmed cases of Zika in the placebo group and the vaccinated group to determine if the trial vaccine protects against the virus.
The NIH expects the study to be completed by 2019.