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Zika vaccine found safe, promising in first human trial

PBR Staff Writer Published 06 October 2017

A DNA-based Zika vaccine, dubbed GLS-5700, developed by a consortium led by Inovio Pharmaceuticals and GeneOne Life Science succeeded in a phase 1 clinical trial by producing anti-Zika response in humans.

The Zika vaccine showed both safety and the ability to induce high levels of antibodies in all the 40 participants of the trial against the mosquito-borne virus in humans who were subjected to up to three doses of GLS-5700.

In a research carried out by the Perelman School of Medicine at the University of Pennsylvania in collaboration with The Wistar Institute, Inovio Pharmaceuticals, and GeneOne Life Science, the vaccine candidate was shown to have minimal adverse effects.

The success in the early stage human trial would now pave way for further clinical trials of the new DNA-based Zika vaccine candidate.

The Wistar Institute executive vice president and Wistar Vaccine & Immunotherapy Center director David Weiner said: “Synthetic DNA vaccines, such as this Zika vaccine candidate our team has developed, are an important approach to preventing emerging infectious diseases.

“This novel DNA vaccine was developed and implemented in just months via a platform that has advantages in temperature stability, storage, dose, and distribution compared to most traditional vaccines, making DNA vaccines an important tool to respond quickly to curb an emerging epidemic.”

According to Inovio, the phase 1 study saw the participants receiving GLS-5700 in a 1mg or 2mg dose by 0.1ml intradermal injections administered by the company’s Cellectra 3P skin vaccine device.

The Pennsylvania-based biotechnology company revealed that serum samples taken from vaccinated patients were found to be protective from death and illness against the Zika virus in over 90% of animals. This was after the serum samples were transferred to mice that were subject with a lethal dose of the virus.

Inovio president and CEO Dr. J. Joseph Kim said: “Results from this published study demonstrate that all human subjects responded to the vaccine and that the immune responses have the ability to confer protection in challenge models.

“A second phase 1 study, now fully enrolled in Puerto Rico, is designed with a placebo control to explore a potential trend towards clinical efficacy. Inovio is proud to be a pioneer of Zika vaccine development, and the first to generate positive human data that clearly supports advancement of DNA technology and our vaccine candidate.”

Image: An Aedes aegypti mosquito that spreads the Zika virus in humans. Photo: courtesy of James Gathany/