Ebola virus, being highly pathogenic for humans and non-human primates and the subject of former weapons programmes, is now one of the most feared pathogens worldwide, states the Department of Medical Microbiology at the University of Manitoba in Canada.
As early as 2000, we knew it was possible to develop an Ebola vaccine.
The Vaccine Research Center, National Institutes of Health, Bethesda, Maryland described a highly effective vaccine strategy for Ebola virus infection in non-human primates. It was challenged with a lethal dose of the highly pathogenic, wild-type, 1976 Mayinga strain of Ebola Zaire virus resulted in uniform infection in controls, who progressed to a moribund state and caused death in less than one week. It was a different with all vaccinated animals who were asymptomatic for more than six months, with no detectable virus after the initial challenge. These findings from this study demonstrated that it is possible to develop a preventive vaccine against Ebola virus infection in primates.
In 2003, perspectives were changed regarding an Ebola virus because of September 2011 events.
The Virology Division at the United States Army Medical Research Institute of Infectious Diseases looked at current Ebola vaccine candidates since the heightened awareness of bio-terrorism advanced by the events surrounding September 11, 2001, concomitant with knowledge that the former Soviet Union was evaluating Ebola virus as a weapon, has dramatically changed perspectives regarding the need for a vaccine against Ebola virus. They stated that the Ebola viruses belong to the family Filoviridae, which are among the most virulent infectious agents known.
In 2006, we developed a vaccine against the Ebola virus for rodents.
The Division of Biodefense Vaccines, GenPhar, Inc performed a study demonstrates the potential efficacy of a bivalent Ebola (EBOV) vaccine based on a cAdVax vaccine vector design. The National Institute of Allergy and Infectious Diseases in Maryland actually funded a study that a DNA vaccination conferred an Ebola virus-specific immune response in guinea pigs and mice. This study also indicates that a protection against a challenge with Ebola virus was adapted to produce a lethal infection in rodents.
In 2009, a Ebola vaccine was developed to protect a cynomolgus monkey.
The Food and Drug Administration requires the use of a non-rodent species, often the dog or monkey because of similarities to specific human biochemical pathways. The non-rodent animals that are considered standard models for toxicology studies include rabbit, dog and monkey, specifically the New Zealand White rabbit, the beagle dog and the cynomolgus monkey. Because these animals have been traditionally used, there is substantial accumulation of historical data and the use of a different animal model could delay approval of a new drug.
At this time, the Department of Microbiology, National Emerging Infectious Diseases Laboratories Institute at the Boston University School of Medicine developed an immunization scheme based on a single-injection vaccine that protects nonhuman primates against lethal challenge with representative strains of all human pathogenic filovirus species.
In 2010, at least four systems have shown the ability to protect non-human primates against lethal Marburg virus and Ebola challenge.
A report, from the Virology Division, United States Army Medical Research Institute of Infectious Diseases provided the first demonstration of vaccine-induced protective immunity against challenge with a heterologous EBOV species, and shows that Ebola vaccines capable of eliciting potent cellular immunity may provide the best strategy for eliciting cross-protection against newly emerging heterologous EBOV species.
In 2013, evidence was provided that proved that the Ebola virus infection in wildlife came from mainland Asia and confirms that filoviruses are harbored across a much larger geographic range then assumed.
The Emerging Viral Pathogens Section at the National Institute of Allergy and Infectious Diseases, National Institutes of Health did a study with mice where the results further support the concept that a successful EBOV vaccine needs to induce strong antibodies against EBOV.
RECOMMENDED READING
No comments:
Post a Comment