Inovio's Zika Virus Vaccine Proves to be Effective in First Human Trial

A DNA-based Zika virus vaccine developed by Inovio Pharmaceuticals has proven successful in phase I open-label dose-ranging human trials. In animal studies, this vaccine was found to prevent Zika virus infection as well as brain damage.

Congenital infection with the Zika virus in known to cause microcephaly, while infection in adults may result in the development of Guillain-Barré Syndrome. More recently, a study published in JAMA Ophthalmology strengthened the link between infection with the Zika virus and significant retinal damage. Approximately 6% of infants born to mothers infected with the Zika virus during pregnancy were shown to have developed birth defects. Because of this, researchers are expending all efforts towards Zika diagnostics and preventive tools.

Earlier this week, a rising biotech company announced that they have designed a device that would be able to detect Zika virus early, and only within 10 minutes; not only this, but the materials needed to create the tool cost only $1. However, measures to protect against Zika virus infection in the first place are of the utmost importance.

In June 2016, Inovio Pharmaceuticals announced that the US Food and Drug Administration approved human trials to evaluate the safety and efficacy of the pharmaceutical company’s DNA-based Zika virus vaccine. Now, the company has confirmed that the vaccine (GLS-5700) “generated robust antigen-specific antibody responses in a first-in-man, multi-center phase I trial.” According to the press release, 40 Zika-naïve adult test subjects were placed in either a low-dose or a high-dose group. After 1 or 2 vaccine doses, subjects from both test groups showed antibody response. The vaccine was found to be well-tolerated, and “no significant safety concerns” were observed in any of the subjects after 14 weeks of vaccine initiation.

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In the press release, J. Joseph Kim, PhD, president and CEO of Inovio Pharmaceuticals commented on the study’s findings, stating, “These early clinical results show that Inovio is on track to rapidly develop Zika countermeasures for this disease that has no currently existing vaccine or treatment. Our synthetic vaccine technology allows rapid development of new products, leading Inovio to be the first to create a Zika vaccine, the first to generate preclinical data, the first to initiate human testing, and now first to report positive clinical data.”

The company is set to conduct a second phase I study in Puerto Rico, which will include 160 test subjects. According to the Centers for Disease Control and Prevention (CDC), approximately 25% of the population in Puerto Rico may be infected with the Zika virus by the end of the year. Dr. Kim stated, “Based on these two studies, we plan to meet with regulators to map out the most efficient path forward to bring our Zika vaccine to patients and help mitigate this widespread Zika outbreak that has expanded into the continental United States.”

At the moment, 33,260 individuals residing in Puerto Rico were reported to have contracted the Zika virus; however, the CDC notes that this number is underreported. The virus has also been circulating in parts of Florida, and more recently, in Texas.