� � Jun-16-2010
Findings of a latest research hints that a trial vaccine developed in Canada to combat the Marburg virus has the potential to remain effective even when it is administered a number of days following the patient's exposure to the lethal disease-bearing microorganism. The experiment, carried out on macaque monkeys, demonstrated that even when the trial inoculation was administered around 48 hours after receiving a chemical that was as potent as the deadly dosage of Marburg virus, it still supported subsistence in a number of the subjects.
Researchers associated with the experiment of the trial vaccine on macaque monkeys are of the view that in the case of humans, the treatment window would be vaster. They further said that clinical trials on humans would not entail giving them large doses of the Marburg virus that was administered to the monkeys. In addition, compared to the monkeys, humans usually take a longer period before they succumb to the deadly virus.
According to Dr. Heinz Feldmann, who headed the team of scientists working on the trial vaccine against the Marburg virus while he was engaged with the National Microbiology Laboratory in Winnipeg in Canada a number of years back, the study has demonstrated that now the vaccine can be effectively administered to people affected by the deadly pathogen even one-and-a-half times or perhaps twice the time after being exposed to the microbe. At the same time, Dr. Feldmann said that the study was still in its nascent stage and everything is just a guesstimate. He further stated that the scientists working on the project were of the opinion that the trial vaccine was likely to be more powerful when administered to humans. However, he said that as of now they did not have any proof regarding this belief.
It may be mentioned here that Dr. Feldmann is specialized in viral hemorrhagic (causing profuse bleeding) fevers and is presently the head of Rocky Mountain Laboratories' virology section. Rocky Mountain Laboratories, situated in Hamilton in Mont, is an arm of the United States National Institute of Allergy and Infectious Diseases. In addition, Dr. Feldmann is also the senior author of the paper published in the medical journal 'Emerging Infectious Diseases'. The co-authors of this article include scientists from the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) located at Fort Detrick, Md., and from the Winnipeg laboratory.
Earlier, the same group of scientists led by Dr. Feldmann had demonstrated that the trial Marburg vaccine and others that are prepare in the same manner also guard humans from the nastiest strains of Ebola virus were also effective in protecting monkeys provided they were given approximately 20 to 30 minutes following the injection of a deadly dosage of the toxic virus. In fact, the earlier researches conducted by the team demonstrated that these inoculations were effective in totally protecting all monkeys against the Marburg as well as Ebola Sudan viruses. In addition, their studies also showed that these vaccines were able to protect 50 per cent of monkeys affected by Ebola Zaire - the deadliest among all the species of Ebola viruses.
However, in reality, it would really be difficult for someone exposed to any of the above mentioned deadly viruses or affected by any of them to find and take a vaccine so promptly. The fact is that even in the specific laboratories that are focused on working with such deadly pathogens, it would take more than 30 minutes to avail and administer any of these vaccines - that are mostly in their trial stages. Here is an instance of what we are exactly talking about. In 2009, when a German scholar stuck herself with a needle infected with Ebola by accident, she was administered the vaccine against the pathogen around 40 hours after the occurrence. In effect, its was only after the Public Health Agency of Canada made a dose of the vaccine available on grounds of compassion and it was rushed by air to Germany that the scholar could be inoculated. Fortunately, the scholar managed to survive after this.
However, what is still undecided is whether the German scholar had actually not been infected by the deadly pathogen or she survived owing to the vaccination. Several laboratories are still endeavouring to unearth the truth regarding the case involving the German scholar. Nevertheless, all attempts to find an answer to this question has proved to be futile and this failure has vexed everyone involved with the search and the inability to ascertain the truth still continues to frustrate them.
According to Dr. Feldmann, several people have asked him and his colleagues regarding their view on the maximum time period regarding the effectiveness of administering the trial vaccine after a person is exposed to the deadly Marburg virus. He said that such queries led them to undertake the studies on monkeys with a view to find the maximum time duration of successfully administering the vaccine after a person has been exposed to the fatal pathogen.
The study headed by Dr. Feldmann involved six macaque monkeys of which five of them were administered the trial vaccine following 24 hours of being given deadly doses of the something similar to the pathogen and they managed to survive. More importantly, two of those six monkeys who were exposed to the fatal Marburg virus and vaccinated 48 hours after the infection also succeeded in surviving. However, all the control monkeys that were exposed to the microbe, but were not given the vaccine succumbed to the deadly pathogen.
According to Dr. Thomas Geisbert, the first author of the study, the findings of the study certainly showed great potential, especially considering the dosage of the virus given to the monkeys. Describing the dose of virus given to the monkeys as an insane amount, Dr. Geisbert said that the models they were using in the laboratories were something like comparable to the completely horrible instance. He said that he considered this to be a highly heartening situation.
However, what appear to be less cheering is the apparently overwhelming problems in the way of the progresses made in the field of science and the aptitude to utilize them to end the Ebola or Marburg epidemics that rage across the different communities in some regions of Africa now and then. In fact, it is likely to cost millions or may be even 10s of millions of dollars to transform the advances made of science into commercial production of vaccines or remedies that may be utilized as a preventive measure against these deadly pathogens or to treat the patients already exposed to the viruses.
The only saving grace is that the Marburg and Ebola epidemics only occur at irregular intervals and only affect in some of the poorest nations of the world. Often, numerous years pass by without any incidence of human exposure to these fatal microbes. Both Dr. Feldmann and Dr. Geisbert are of the view that thus far there is no commercial system for developing a vaccine or medication to put off or cure such atypical and capricious maladies like the Ebola or Marburg outbreaks.
Since the Ebola and Marburg outbreaks are rare and also affect the poorest nations, there is hardly anyone who would be interested in investing money in commercial development and manufacture of vaccines and medications against these fatal pathogens. According to Dr. Geisbert, who is also the associate director of the National Emerging Infectious Diseases Laboratories Institute at the Boston University, the reason behind this is not difficult to understand - actually no one would be making huge money by developing such vaccines or drugs. Dr. Geisbert, who was previously associated with the United States Army Medical Research Institute of Infectious Diseases (USAMRIID), developing vaccines and drugs against the Marburg and Ebola outbreaks would finally require government sponsorships.
It may be noted that the deadly viruses such as the Ebola and Marburg are being regarded as bioterrorism risks and, hence, the scientists anticipate that the governments would allocate a portion of their defence budgets to help developing vaccines as well as potential drugs against them. Meanwhile, Dr. Geisbert says that the government also needs to help experiment the trial vaccine developed by Dr. Feldmann and his colleagues to the ensuing stage wherein it would be possible to undertake testing that would endorse licensure applications. However, it is really unfortunate to note that currently the researchers are feeling as if their endeavours to develop an effective vaccination or drug against these deadly pathogens are being put off.
Meanwhile, Dr. Feldmann said that as far as he is concerned, the progress in developing an effective vaccine or drug against these lethal viruses is very sluggish. He further said that as of now he does not see anyone actually intensifying further research in this field or doing anything regarding finding a cure against the maladies caused by such deadly pathogens. It may be mentioned here that Dr. Feldmann possesses vast understanding in the domain of containing the Ebola and Marburg epidemics. Being fully aware of the fact that without solid sponsorship scientists are only able to carry their work forward up to a certain stage and no further, Dr. Geisbert shares the disappointment of Dr. Feldmann. Appearing completely hopeless, Dr. Geisbert concluded that there is 'nothing in their hands'.