Research on DNA-based Zika Virus Vaccine Yields Positive Results

A vaccine for Zika virus is hardly around the corner, but research initiatives seeking a viable candidate continue to yield positive results.

In a study published November 10th by the journal npj Vaccines, researchers from the University of Pennsylvania Perelman School of Medicine and the Wistar Institute announced that a vaccine based on synthetic Zika viral DNA was found to be protective against infection, brain damage, and mortality in mouse models. Experts say the study is the first to demonstrate that such a vaccine is safe and effective in an animal model susceptible to Zika.

The DNA-based vaccine is one of several currently in development and being evaluated for use in humans. It is being developed via a collaborative effort between biotech firms Inovio, GeneOne, and Wistar that has received federal funding for its Zika-related efforts. In June, the partnership announced that it had received US Food and Drug Administration approval to start Phase I human trials for the vaccine, and two trials have already begun—one in Puerto Rico involving 160 subjects and a second, 40-subject trial in the continental United States and Canada.

To date, all results have been promising. In the preclinical study published in Nature, for example, in mouse models, David B. Weiner, PhD, of Wistar and the University of Pennsylvania, and colleagues found that the synthetic DNA vaccine expressed specific antigens for Zika in vivo, which effectively neutralized the virus and prevented it from spreading to the brains of the mouse models used—the latter being notable due to the neurologic complication associated with the mosquito-borne infection. In fact, they observed that 100% of the animal models in the study were protected after vaccination followed by a challenge with the Zika virus. All of the mouse models were also protected from cerebral cortex and hippocampal degeneration, which the unvaccinated mice controls experienced after Zika infection.

Dr. Weiner could not be reached for comment at press time. However, in a statement released by Inovio in conjunction with the study’s publication, he noted, “Our results support the critical importance of immune responses for both preventing infection as well as ameliorating disease caused by the Zika virus. As the threat of Zika continues, these results further encourage the study of this vaccine as a preventative approach for protecting humans.”

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.

Editor’s note: The following errors in the original version of this article have been corrected: The study was reported as being published in the journal, Nature, when in fact the study was published in the journal, npj Vaccines.