April 14, 2005
Largest Marburg Virus Outbreak To Date Has No End In Sight: Is There A Vaccine On The Horizon?Topics: Health Issues
High mortality rates and lack of an available vaccine against Marburg hemorrhagic fever highlight the need for a defensive therapy against Marburg hemorrhagic fever and greater knowledge of the causative agent, the Marburg virus. With disease experts struggling to contain a deadly outbreak of the Marburg virus that has killed at least 194 people in Angola midst concerns that it will take weeks to determine whether the disease can be stamped out before it becomes a long-term crisis, is there any hope for a vaccine in time to help the current threat of a pandemic ? Probably not, but work is progressing on the development of a vaccine that could lead to a multi-agent vaccine capable of simultaneously protecting against multiple and diverse members of the Filoviridae family(includes Marlburg and Ebola viruses) for future outbreaks. It has already been shown that expression of the homologous glycoprotein and matrix protein VP40 from a single filovirus, either EBOV or MARV, resulted in formation of wild-type virus-like particles in mammalian cells. When used as a vaccine, the wild-type VLPs protected from homologous filovirus challenge. Newer work is even more promising.
Dan at Riehl World View has been folowing the Marburg virus problem closely. His post today addresses the issue of Angola's outbreak of the deadly virus having reached a point at which it is now the largest and most deadly in history - and is said to still be peaking. The fight against the virus is complicated by its outbreak in a poor urban environment of 200,000, most without running water or electricity and the World Health Organization (WHO) has issued warnings for travelers.
"Whole families have died. This is very traumatic for the local population," she said.
It is also being reported that this could develop into a long term problem.
Uige - There is no end in sight to the outbreak of the Marburg virus in Angola, a top expert from the World Health Organisation said on Wednesday, citing "massive problems" in mobilising Angolans to fight the Ebola-like bug in this northern city.
"After four weeks, this epidemic is still peaking," said Pierre Formenty, the WHO's top specialist on new and dangerous diseases. "It has not been stopped, because we have massive problems in mobilising the community against it," he told AFP as the death toll from the deadly haemorrhagic fever hit 210.
The present outbreak of Marburg haemorrhagic fever is unprecedented in its size and urban nature, and its dimensions are still unfolding. Although surveillance to detect cases has improved, it remains patchy.
In Uige, where daily mobile teams are active, surveillance continues to be largely concentrated on the investigation of deaths and collection of bodies. The security of teams remains a concern. More vehicles are needed and WHO is making the necessary arrangements on an urgent basis.
Officials also say that the next few weeks are critical and if the outbreak is not contained it could become a long-term problem. More at Dan's Riehl World View ....
While the epidemic in Angola continues unabated, researchers at the United States Army Medical Research Institute of Infectious Diseases in Frederick, MD believe that their recent work provides a critical foundation towards the development of a pan-filovirus vaccine that is safe and effective for use in primates and humans.
Their initial approach was to construct hybrid virus-like particles(not the whole virus) containing heterologous viral proteins, of the Ebola and Marburg viruses, and test the efficacy of the hybrid virus-like particles in a guinea pig model (Ebola and Marburg viruses are the sole members of the genus Filovirus in the family Filoviridae). Their data indicates that vaccination with the glycoprotein was required and sufficient to protect against a homologous filovirus challenge, as heterologous wild-type virus-like particles or hybrid virus-like particles that did not contain the homologous glycoprotein failed to protect against challenge.
Alternately, the researchers vaccinated guinea pigs with a mixture of wild-type Ebola and Marburg virus-like particles, and found that vaccination with a single dose of the multivalent virus-like particle vaccine elicited strong immune responses to both viruses and protected animals against challenges by both the Ebola and Marlburg viruses.
I believe that we should be concerned over the very strong possibility, maybe even probability, that the Marlburg and Ebola viruses are potential tools for bioterrorism. Just think, what if they were effective as an aerosol? Problem, because they are!
Read - Marburg and Ebola viruses as aerosol threats.
Posted by Hyscience at April 14, 2005 9:11 AM
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- Largest Marburg Virus Outbreak To Date Has No End In Sight: Is There A Vaccine On The Horizon? - Apr 14, 2005