Results of a study published in today’s issue of the journal Nature demonstrate that a single dose of vaccine administered using Perfectus BioSciences’ VesiculoVax vector platform protects non-human primates against the “Makona” strain of Ebola virus, the strain responsible for the current Ebola outbreak in West Africa.
Profectus BioSciences, Inc. is a clinical-stage vaccine company developing novel vaccines for the treatment and prevention of infectious diseases. The study was authored by researchers at Profectus and the University of Texas Medical Branch (UTMB) at Galveston.
“A key goal in efforts to address the 2014-2015 outbreak of the highly lethal Zaire Ebola virus has been to develop a preventive vaccine that rapidly confers protection in a single administration,” said John Eldridge, PhD, Chief Scientific Officer of Profectus. “This is the first demonstration of a vaccine that is able to rapidly confer single-dose protection against the current Makona strain of Zaire Ebola virus that is responsible for more than 10,000 deaths in the ongoing epidemic in West Africa.
The highly immunogenic VesiculoVax vaccine delivery system was developed for emerging infectious disease indications where the rapid induction of neutralizing antibodies is needed to protect against the viruses that cause hemorrhagic fevers such as Ebola, Marburg, and Lassa; encephalitic disease (VEE, EEE, WEE); and arthralgic disease (Chikungunya). VesiculoVax vaccines are based on replication-competent recombinant vesiculoviruses that have been genetically attenuated so as not to cause illness in animals or humans.
The company’s VesiculoVax vaccines for pre- and post-exposure protection against the Ebola viruses is based on a form of vesicular stomatitis virus (rVSV) engineered to express the surface protein from the Zaire and Sudan variants of the Ebola virus.
In this trial, two candidate VesiculoVax-vectored Ebola vaccines of intermediate and high attenuation were tested, and both were shown to provide complete, single-dose protection of rhesus macaques from the Makona strain of Ebola from Guinea.
Eight vaccinated and two unvaccinated control macaques were infected with a Makona strain of Ebola virus 28 days after receiving a single injection of one of the vaccines. None of the monkeys vaccinated with either vaccine showed any severe signs of illness following infection with the virus, whereas the two unvaccinated animals succumbed to the disease on days seven and eight.
Profectus’ highly attenuated rVSVN4CT1 VesiculoVax vector used in this study is also the foundation of the Profectus Ebola and Marburg monovalent and trivalent vaccines in development by Profectus with support from the National Institutes of Health (NIH), the U.S. Department of Health and Human Services (HHS) Biomedical Advanced Research and Development Authority (BARDA), and the Department of Defense (DoD) Joint Vaccine Acquisition Program (JVAP).
The VesiculoVax platform provides the flexibility to construct vaccine delivery vectors with different levels of attenuation, a capability that enables the identification of vaccines that provide complete protection with the highest level of safety.
“We are grateful to the Geisbert laboratory at UTMB for its unrestricted collaboration, and we are excited about the potential of our vaccine to combat the current outbreak,” continued Eldridge. We look forward to continued rapid progress to advance this vaccine—along with our trivalent vaccine for protection against all Ebola and Marburg viruses—into human clinical trials.”
Read the study at Nature: Single-Dose Attenuated VesiculoVax Vaccines Protect Primates Against Ebola Makona Virus.
