(Press-News.org) MADISON, Wis. -- An Ebola whole virus vaccine, constructed using a novel experimental platform, has been shown to effectively protect monkeys exposed to the often fatal virus.
The vaccine, described today (March 26, 2015) in the journal Science, was developed by a group led by Yoshihiro Kawaoka, a University of Wisconsin-Madison expert on avian influenza, Ebola and other viruses of medical importance. It differs from other Ebola vaccines because as an inactivated whole virus vaccine, it primes the host immune system with the full complement of Ebola viral proteins and genes, potentially conferring greater protection.
"In terms of efficacy, this affords excellent protection," explains Kawaoka, a professor of pathobiological sciences in the UW-Madison School of Veterinary Medicine and who also holds a faculty appointment at the University of Tokyo. "It is also a very safe vaccine."
The vaccine was constructed on an experimental platform first devised in 2008 by Peter Halfmann, a research scientist in Kawaoka's lab. The system allows researchers to safely work with the virus thanks to the deletion of a key gene known as VP30, which the Ebola virus uses to make a protein required for it to reproduce in host cells. Ebola virus has only eight genes and, like most viruses, depends on the molecular machinery of host cells to grow and become infectious.
By engineering monkey kidney cells to express the VP30 protein, the virus can be safely studied in the lab and be used as a basis for devising countermeasures like a whole virus vaccine. The vaccine reported by Kawaoka and his colleagues was additionally chemically inactivated using hydrogen peroxide, according to the new Science report.
Ebola first emerged in 1976 in Sudan and Zaire. The current outbreak in West Africa has so far claimed more than 10,000 lives. There are no proven treatments or vaccines, although several vaccine platforms have been devised in recent years, four of which recently advanced to the clinical trial stage in humans.
The new vaccine reported by Kawaoka has not been tested in people. However, the successful tests in nonhuman primates conducted at the National Institutes of Health (NIH) Rocky Mountain Laboratories, a biosafety level 4 facility in Hamilton, Montana, may prompt further tests and possibly clinical trials of the new vaccine. The work at Rocky Mountain Laboratories was conducted in collaboration with a group led by Heinz Feldmann of NIH.
Those studies were conducted with cynomolgus macaques, which are very susceptible to Ebola. "It's the best model," Kawaoka says. "If you get protection with this model, it's working."
Ebola vaccines currently in trials include:
--A DNA-based plasmid vaccine that primes host cells with some of the Ebola proteins.
--A vaccine based on a replication incompetent chimpanzee respiratory virus engineered to express a key Ebola protein.
--A live attenuated virus from the same family of viruses that causes rabies, also engineered to express a critical Ebola protein.
--A vaccine based on a vaccinia virus and engineered to express a critical Ebola protein.
Each of those strategies, Kawaoka notes, has drawbacks in terms of safety and delivery.
Whole virus vaccines have long been used to successfully prevent serious human diseases, including polio, influenza, hepatitis and human papillomavirus-mediated cervical cancer.
The advantage conferred by inactivated whole virus vaccines such as the one devised by Halfmann, Kawaoka and their colleagues is that they present the complete range of proteins and genetic material to the host immune system, which is then more likely to trigger a broader and more robust immune response.
Early attempts to devise an inactivated whole virus Ebola vaccine through irradiation and the preservative formalin failed to protect monkeys exposed to the Ebola virus and were abandoned.
Although the new vaccine has surpassed that hurdle, human trials are expensive and complex, costing millions of dollars.
INFORMATION:
The Ebola vaccine study conducted by Kawaoka was supported by the National Institutes of Health and by the Japanese Health and Labour Sciences Research Grants.
In addition to Kawaoka, co-authors of the new Science report include Halfmann, Lindsay Hill-Batorski and Gabriele Neumann of UW-Madison and Andrea Marzi, W. Lesley Shupert and Feldmann of the National Institute of Allergy and Infectious Diseases.
CONTACT: Yoshihiro Kawaoka, kawaokay@svm.vetmed.wisc.edu
Terry Devitt, 608-262-8282, trdevitt@wisc.edu
Orchestrated costume changes make it possible for certain nasty microbes to outsmart the immune system, which would otherwise recognize them by the telltale proteins they wear. By taking the first detailed look at how one such parasite periodically assumes a new protein disguise during a long-term infection, new research at Rockefeller University challenges many assumptions about one of the best-known examples of this strategy, called antigenic variation, in the parasite that causes African sleeping sickness.
For research published on March 27 in Science, a team at Rockefeller ...
A new study led by Scripps Institution of Oceanography at UC San Diego researchers has revealed that the thickness of Antarctica's floating ice shelves has recently decreased by as much as 18 percent in certain areas over nearly two decades, providing new insights on how the Antarctic ice sheet is responding to climate change.
Data from nearly two decades of satellite missions have shown that the ice volume decline is accelerating, according to a study published on March 26, 2015, in the journal Science and supported by NASA. Scripps graduate student Fernando Paolo, Scripps ...
HOUSTON - (March 26, 2015) - Taking out the garbage is a crucial step in housecleaning.
Similarly, autophagy is the body's first-line of defense against the buildup up of toxic substances, degrading old organelles and proteins to provide new substrates and building blocks. In this way, autophagy prevents the buildup of "garbage" that can result in destruction of neurons and cause neurologic diseases.
A forward genetic screen in Drosophila melanogaster (fruit flies) identified mutant copies, or alleles, of a gene called cacophony associated with defects in autophagy ...
While most of us recover from influenza after a week, it can be a very severe disease, and even fatal in rare cases, with no reason for physicians to have expected such an outcome. By analysing the genome of a little girl who contracted a severe form of influenza at the age of two and a half years, researchers at the Laboratory of Human Genetics of Infectious Diseases (a joint French-American international laboratory), which brings together researchers from Inserm, Paris Descartes University, and physicians from the Paris public hospitals (AP-HP; Necker Hospital for Sick ...
New research shows bacteria can use tiny magnetic particles to effectively create a 'natural battery.' According to work published in journal Science on 27 March, the bacteria can load electrons onto and discharge electrons from microscopic particles of magnetite. This discovery holds out the potential of using this mechanism to help clean up environmental pollution, and other bioengineering applications. The European Association of Geochemistry is highlighting this work as especially interesting.
According to study leader Dr James Byrne (Tübingen):
"The geochemistry ...
A study led by Cathy Spatz Widom, Distinguished Professor of Psychology at John Jay College, found that offspring of parents with histories of child abuse and neglect are themselves at risk for childhood neglect and sexual abuse but not physical abuse. Titled "Intergenerational Transmission of Child Abuse and Neglect: Real or Detection Bias?" the study's findings were reported in the March 27 issue of the journal Science.
As part of a prospective longitudinal study, Widom followed a large group of children with documented cases of childhood abuse and neglect and a demographically ...
A new study, published today in the journal PloS Neglected Tropical Diseases has given new insights into the spread of rabies in the Middle East, showing that the deadly disease regularly moves between countries in the region.
The international team of researchers including scientists from the University of Surrey and the Animal and Plant Health Agency, have mapped the spread of rabies in the region to help inform control methods.
Previous studies have demonstrated that rabies, a fatal disease transmitted by the bite or scratch from an infected animal, still kills approximately ...
Dark matter is one of science's great mysteries. It makes up an enormous amount matter in the universe, it is invisible, and it does not correspond to anything in the realm of our experience. Different theories compete for an explanation, but so far none of them has prevailed. In a collaborative study between École Polytechnique Fédérale de Lausanne (EPFL) and the University of Edinburgh, scientists have studied how dark matter behaves when galaxy clusters collide with each other over billions of years. Published in Science, their findings challenge at least ...
Foraging bats obey their own set of 'traffic rules', chasing, turning and avoiding collisions at high speed, new research from the University of Bristol, UK has found.
Dr Marc Holderied of Bristol's School of Biological Sciences studied pairs of Daubenton's bats (Myotis daubentonii) foraging low over water for stranded insects at a site near the village of Barrow Gurney in Somerset, UK.
He said: "Collective movements of flocking birds or shoaling fish are amongst the most fascinating natural phenomena, and everyone has experienced the challenges of walking through ...
CHAPEL HILL, NC - A team of researchers has discovered HIV can begin replicating in the brain as early as four months after initial infection. The study followed 72 treatment naïve participants during the first two years of HIV infection. Through analysis of cerebral spinal fluid (CSF) and blood samples, 20 percent of subjects showed replication in the central nervous system (CNS) at four months. Additionally, 30 percent of participants showed evidence of a marked CSF inflammatory response in at least one time point and 16 percent of study volunteers showed a marked ...
