PLYMOUTH MEETING, Pa.—Inovio Pharmaceuticals Inc., and Tarrytown, N.Y.-based TechnoVax Inc. have both recently announced promising research findings indicating a Zika vaccine may be on the horizon. No vaccine or therapy currently exists for the prevention or treatment of Zika virus infection, which has taken hold in 68 countries around the globe.
While the disease is rarely fatal for adults, it has been linked to thousands of babies being born with microcephaly, categorized by babies being born with below-average head size and underdeveloped brains. This can cause intellectual disability, developmental delays and sometimes death when the brain cannot regulate vital life functions. Zika has proven to be particularly hard to prevent because it can be sexually transmitted before a person is symptomatic, and can persist in the male reproductive tract for weeks or months after infection. In addition, it can damage the testes and sperm of infected males.
Inovio’s vaccine aims to protect against these complications. Their DNA-based Zika vaccine (GLS-5700) appears to protect against Zika virus-induced damage to testes and sperm, and it prevented persistence of the virus in the reproductive tract of all vaccinated male mice challenged with a high dose of the Zika virus. This preclinical study data was published in Nature Communications in an article entitled, “DNA Vaccination Protects Mice Against Zika Virus-Induced Damage to the Testes,” written by Inovio scientists and collaborators.
Dr. Gary Kobinger, lead author of the study and director of the Centre for Research in Infectious Diseases at Canada’s Laval University in Quebec City, said, “Given that we know that Zika virus infection can involve the male reproductive tract and persist in humans for several months after onset of infection, this preclinical data warrants further examination as a potential means to reduce Zika virus infection of the male reproductive tract and the risk of sexual transmission of the virus.”
GLS-5700 has previously been shown to protect mice against infection, brain damage and death after exposure to the virus, through its ability to leverage the body’s naturally existing mechanisms to generate robust, highly targeted immune responses to prevent and treat disease—and to do so in the body with a favorable safety profile. These additional findings regarding the male reproductive tract indicate broader promise for the vaccine than previously thought.
Inovio is joined in the race to find an effective vaccine by researchers at the City College of New York (CUNY) School of Medicine in collaboration with TechnoVax. Preclinical trials in animal models demonstrate favorable outcomes in developing a vaccine against Zika using TechnoVax’s proprietary virus-like particles (VLPs).
TechnoVax and its team of scientists have developed a new way to produce highly immunogenic, non-infectious monovalent and polyvalent VLP vaccines using a cell-based manufacturing system. VLPs are structures that mimic the organization and conformation of native viruses but are non-infectious because they do not contain any viral genetic material, potentially yielding safer and cheaper vaccine candidates. The ultimate goal of the collaboration with CUNY is to expand the translational research with TechnoVax by completing the Zika vaccine development and initiate new vaccine projects directed to additional virus pathogens.
The VLP vaccine formulations tested in animals not only were highly effective in eliciting protective antibodies with neutralizing activity equivalent to or higher than the activity present in the serum of a patient who recovered from Zika infection, but also were well tolerated and safe. “The ZIKA VLP vaccine offers an effective and safe strategy to create a prophylactic vaccine that protects against Zika infection as well as its serious effects, such as microcephaly,” said Jose M. Galarza, TechnoVax CEO.
First identified in Uganda in 1947, Zika virus subsequently spread to equatorial Asia and in recent years through the South Pacific, Hawaii, South America, Central America and Caribbean. In 2016, local mosquito-borne transmission occurred in North America in Florida and Texas. Zika virus is a flavivirus, a family of viruses including yellow fever, dengue and West Nile virus, which are introduced to people through mosquito bites. Unlike other flaviviruses, Zika virus can be sexually transmitted. As of December 2016, 68 countries and territories reported continuing mosquito-borne transmission of the Zika virus, compared to 33 countries stated by the World Health Organization in their first Zika situation report in February 2016.