 |
|
Penn animal study identifies new DNA weapon against avian flu
July 02, 2008Broad application of DNA vaccine could allow for quick mobilization during an epidemic
PHILADELPHIA - Researchers at the University of Pennsylvania School of Medicine have identified a potential new way to vaccinate against avian flu. By delivering vaccine via DNA constructed to build antigens against flu, along with a minute electric pulse, researchers have immunized experimental animals against various strains of the virus. This approach could allow for the build up of vaccine reserves that could be easily and effectively dispensed in case of an epidemic. This study was published last week in PLoS ONE.
"This is the first study to show that a single DNA vaccine can induce protection against strains of pandemic flu in many animal models, including primates," says David B. Weiner, Ph.D., Professor of Pathology and Laboratory Medicine. "With this type of vaccine, we can generate a single construct of a pandemic flu vaccine that will give much broader protection."
Traditional vaccines expose a formulation of a specific strain of flu to the body so it can create immune responses against that specific strain. Conversely, a DNA vaccine becomes part of the cell, giving it the blueprint it needs to build antigens that can induce responses that target diverse strains of pandemic flu.
Avian flu is tricky. Not only is it deadly, but it mutates quickly, generating different strains that escape an immune response targeted against one single strain. Preparing effective vaccines for pandemic flu in advance with either live or killed viruses, which protect against only one or few cross-strains, is therefore very difficult. How to predict which strain of avian flu may appear at any time is difficult. "We are always behind in creating a vaccine that can effectively protect against that specific strain," notes Weiner.
Instead of injecting a live or killed virus, Penn researchers injected three different species of animal models with synthetic DNA vaccines that are not taken from the flu microbe, but trick the immune system into mounting a broad response against pandemic flu, including strains to which the immune system was never exposed. Antibodies induced by the vaccine rapidly reached protective levels in all three animal species.
"The synthetic DNA vaccines designed in this study customize the antigen to induce more broad immune responses against the pathogen," says Weiner.
Researchers found evidence of two types of immune responses - T lymphocytes and antibodies -- in all three types of animal models. Two types of animal models (mice and ferrets) were protected from both disease and mortality when exposed to avian flu.
To ensure increased DNA delivery, the researchers administered the vaccine in combination with electroporation, a small, harmless electric charge that opens up cell pores facilitating increased entry of the DNA vaccine into cells.
If proven in humans, this research could lead the way to preparing against an outbreak of avian flu. Because these synthetic DNA vaccines are effective against multiple cross strains, vaccines could be created, stockpiled, prior to a pandemic, and thus be delivered quickly in the event of an outbreak, surmise the researchers.
This study has shown other advantages of DNA vaccines. On one hand, killed vaccines, which involve the injection of a dead portion of a virus, are relatively safe but usually effective at producing only a strong cellular immunity. Live vaccines, which involve the injection of a form of a live virus, can have increased manufacturing and some safety issues. Both of these vaccine strategies may have concerns in persons with certain allergies (egg for example) as current manufacturing methods rely on egg based production technologies. On the other hand, DNA vaccines preclude the need to create live tissue samples, which presents risk to those working with the virus.
"DNA vaccines have the benefits and avoid many conceptual negatives of other types of traditional vaccines," says Weiner.
This research also has implications for non-avian types of flu. Every year, scientists try to guess what strain of the year will be that creates the common flu. Sometimes their educated guess is wrong, which is why last year's influenza vaccine worked only 30 percent of the time. Designing traditional vaccines in combination with the DNA platform may be a partial solution to this dilemma, predicts Weiner.
University of Pennsylvania School of Medicine
Traditional vaccines expose a formulation of a specific strain of flu to the body so it can create immune responses against that specific strain. Conversely, a DNA vaccine becomes part of the cell, giving it the blueprint it needs to build antigens that can induce responses that target diverse strains of pandemic flu.
Avian flu is tricky. Not only is it deadly, but it mutates quickly, generating different strains that escape an immune response targeted against one single strain. Preparing effective vaccines for pandemic flu in advance with either live or killed viruses, which protect against only one or few cross-strains, is therefore very difficult. How to predict which strain of avian flu may appear at any time is difficult. "We are always behind in creating a vaccine that can effectively protect against that specific strain," notes Weiner.
Instead of injecting a live or killed virus, Penn researchers injected three different species of animal models with synthetic DNA vaccines that are not taken from the flu microbe, but trick the immune system into mounting a broad response against pandemic flu, including strains to which the immune system was never exposed. Antibodies induced by the vaccine rapidly reached protective levels in all three animal species.
"The synthetic DNA vaccines designed in this study customize the antigen to induce more broad immune responses against the pathogen," says Weiner.
Researchers found evidence of two types of immune responses - T lymphocytes and antibodies -- in all three types of animal models. Two types of animal models (mice and ferrets) were protected from both disease and mortality when exposed to avian flu.
To ensure increased DNA delivery, the researchers administered the vaccine in combination with electroporation, a small, harmless electric charge that opens up cell pores facilitating increased entry of the DNA vaccine into cells.
If proven in humans, this research could lead the way to preparing against an outbreak of avian flu. Because these synthetic DNA vaccines are effective against multiple cross strains, vaccines could be created, stockpiled, prior to a pandemic, and thus be delivered quickly in the event of an outbreak, surmise the researchers.
This study has shown other advantages of DNA vaccines. On one hand, killed vaccines, which involve the injection of a dead portion of a virus, are relatively safe but usually effective at producing only a strong cellular immunity. Live vaccines, which involve the injection of a form of a live virus, can have increased manufacturing and some safety issues. Both of these vaccine strategies may have concerns in persons with certain allergies (egg for example) as current manufacturing methods rely on egg based production technologies. On the other hand, DNA vaccines preclude the need to create live tissue samples, which presents risk to those working with the virus.
"DNA vaccines have the benefits and avoid many conceptual negatives of other types of traditional vaccines," says Weiner.
This research also has implications for non-avian types of flu. Every year, scientists try to guess what strain of the year will be that creates the common flu. Sometimes their educated guess is wrong, which is why last year's influenza vaccine worked only 30 percent of the time. Designing traditional vaccines in combination with the DNA platform may be a partial solution to this dilemma, predicts Weiner.
University of Pennsylvania School of Medicine
Avian Flu Current Events and Avian Flu News RSSExon-skipping drug prevents muscle wasting, maintains muscle function in dystrophin deficient mice
An exon skipping PPMO has demonstrated dramatic effects in the prevention and treatment of severely affected, dystrophin and utrophin-deficient mice, preventing severe deterioration of the treated animals and extending their lifespan.
World will miss 2010 target to stem biodiversity loss, experts say
The world will miss its agreed target to stem biodiversity loss by next year, according to experts convening in Cape Town for a landmark conference devoted to biodiversity science.
Avian influenza strain primes brain for Parkinson's disease
At least one strain of the H5N1 avian influenza virus leaves survivors at significantly increased risk for Parkinson's disease and possibly other neurological problems later in life.
Milwaukee swine flu testing results published
Researchers at The Medical College of Wisconsin in Milwaukee published the first initial paper describing the Milwaukee prevalence of the largest outbreak of novel swine origin influenza virus (S-OIV) in America.
Arthritis drug might prove effective in fighting the flu, study suggests
Researchers at the University of Maryland School of Medicine have found that an approved drug for treating rheumatoid arthritis reduces severe illness and death in mice exposed to the Influenza A virus.
New 3-D structural model of critical H1N1 protein developed
In just two weeks from the time the first patient virus samples were made available, Singapore scientists report an evolutionary analysis of a critical protein produced by the 2009 H1N1 influenza A virus strain.
The challenges of avian influenza virus: Mechanism, epidemiology and control
The latest special issue of Science in China Series C: Life Sciences focuses on the recent progress in the H5N1-related research field.
New infectious diseases - what's the risk?
With the current outbreak of swine flu, and in the absence of a vaccine or treatment at present, the only way to contain the virus is to get people around the world to take precautionary measures.
Human nose too cold for bird flu, says new study
Avian influenza viruses do not thrive in humans because the temperature inside a person's nose is too low, according to research published today in the journal PLoS Pathogens.
Avian Flu Research Sheds Light on Swine Flu Outbreak
A recent study by University of Maryland researchers examines the mechanisms underlying transmission of combined avian-human viruses and illustrates how virus outbreaks like that of the current swine flu come about.
More Avian Flu Current Events and Avian Flu News Articles
 |
The Fatal Strain: On the Trail of Avian Flu and the Coming Pandemic by Alan Sipress (Author) A riveting account of why science alone can't stop the next pandemic When avian flu began spreading across Asia in the early-2000s, it reawakened fears that had lain dormant for nearly a century. During the outbreak's deadliest years, Alan Sipress chased the virus as it infiltrated remote jungle villages and teeming cities and saw its mysteries elude the world's top scientists. In The Fatal Strain, Sipress details how socioeconomic and political realities in Asia make it the perfect petri dish in which the fast-mutating strain can become easily communicable among humans. Once it does, the ease and speed of international travel and worldwide economic interdependence could make it as destructive as the flu pandemic of 1918. In his vivid portrayal of the struggle between man... |
 |
Dread: How Fear and Fantasy have Fueled Epidemics from the Black Death to the Avian Flu by Philip Alcabes (Author) The average individual is far more likely to die in a car accident than from a communicable disease…yet we are still much more fearful of the epidemic. Even at our most level-headed, the thought of an epidemic can inspire terror. As Philip Alcabes persuasively argues in Dread, our anxieties about epidemics are created not so much by the germ or microbe in question—or the actual risks of contagion—but by the unknown, the undesirable, and the misunderstood. Alcabes examines epidemics through history to show how they reflect the particular social and cultural anxieties of their times. From Typhoid Mary to bioterrorism, as new outbreaks are unleashed or imagined, new fears surface, new enemies are born, and new behaviors emerge. Dread dissects the fascinating story of the imagined... |
 |
The Next Plague - Avian Flu (History Channel) With the current threat of Avian Flu spreading worldwide, President Bush talked openly about the possibility of an epidemic in the coming years. The Center for Disease Control and the World Health Organization say that we are long overdue for a deadly epidemic, and it isn't a question of if but when. Here in the US the questions are already being asked. Are we ready? How can we prevent it? What will be the cost in lives? We'll look at what effect a large-scale epidemic would have on the United States and the rest of the world. We'll ask what steps pharmaceutical companies are taking in developing vaccines and an antidote. If a nationwide quarantine is put into effect, who will enforce it--the National Guard? We also examine new evidence that the Great Epidemic of 1918 may have been an... |
|
Dread: How Fear and Fantasy Have Fueled Epidemics from the Black Death to Avian Flu by Philip Alcabes (Author) | |
 |
Latex Gloves, Lightly Powdered, 100 per box. recommendation to protect against Avian Bird Flu. by LDF INDUSTRIES INC. Excellent fit for comfort sensitivity & safety; High anti tear properties; Beaded cuff for tear resistance. |
 |
Disposable EARLOOP Face MASK, Filters Bacteria 3 Ply - (Box of 50) by EVERREADY FIRST AID Tie-on surgical face mask with high bacterial filtration efficiency (BFE), low breathing resistance, soft, odorless, non-irritating, comfortable superior fit, fiberglass free. |
 |
Pandemic Influenza, Swine Flu, Avian Flu Kit / Protective Apparel Emergency Disaster and First Aid Protection, Survival Transit Set with 1 Ex. Lg. Full Length Protective Coverall, 1 Face Mask with Eye Shield, 1 Pair of Lg. Gloves, 1 Pair of Lg. Shoe Covers - Safety Toggs / Frogg Toggs Brand - Polyspun Breathable Synthetic Fabric Disposable Set by Safety Toggs / Frogg Toggs Brand Product A Factory Sealed Brand New Safety Toggs / Frogg Toggs Brand Portable Home, Travel and Glovebox First Aid and Emergency Survival and Emergency Preparedness Disaster Accessory. This is a Basic Emergency Flu, Germ - Disease Emergency Disposable Apparel Kit. All Components are Extra Large, the Full Length Coverall Features a Polyspun Fabric Covered Neck to Crotch Zipper. These Components Are NOT WATERPROOF.. The Largest Test Subject we could find was 5" 11" tall, 44/46" waisted, and a shy bit under 300 lbs, they fit snugly but closed just fine, The Coverall's feature the Safety Toggs / Frogg Toggs Brand Name Logo. The Gloves fit most Lg./Ex. Large Hands, The Mask Fits Most Adults, and the Shoe Covers fit Men's Size 10 to 12. Great for Fast Evacuation and Transit, Self Rescue, and... |
 |
10-Pack NIOSH N95 Respirator Flu Face Mask - Exhalation Valve for More Natural Breathing - Double Strap for Secure Fit by Major National Institute for Occupational Safety and Health (NIOSH) approved N95 disposable particulate respirator, approval numbers 84A-4274. Boxed 10 masks per package. |
 |
Fatal Contact: Bird Flu in America Directed By: Richard Pearce Also With: Dennis A. Brown (Producer) |
 |
Avian Influenza Virus (Methods in Molecular Biology) by Erica Spackman (Editor) With the growing global fear of a major pandemic, avian influenza virus research has increased greatly in importance during this young century. In "Avian Influenza Virus", an expert team of researchers and diagnosticians examine the fundamental yet essential virological methods for AI virus research and diagnostics as well as some of the newest molecular procedures currently used for basic and applied research. Exciting, cutting-edge new methods focus on studying the virus itself and work with avian hosts, an area greatly lacking in research. Following the format of the highly successful "Methods in Molecular Biology" series, each chapter provides readily reproducible laboratory protocols offering step-by-step instruction and lists of the necessary equipment for the task. Comprehensive... |
| © 2009 BrightSurf.com |