By: Seth Hays for Medtech1
Researchers in Germany and the United States are "killing two birds with one stone" with a new vaccine that protects birds against certain strains of bird flu and Newcastle disease - a lethal virus among poultry. Perhaps the idiom should be changed to: Saving millions of birds with one vaccine.
|Advice about bird flu from the Mayo Clinic:|
Stay calm: The World Health Organization (WHO) has confirmed a handful of cases of limited human-to-human transmission of bird flu. But unless the virus begins to spread more easily among people, infected birds or material present the greatest hazard.
Avoid contact with sick birds or with surfaces contaminated by their feathers, saliva or droppings.
If you are traveling, or have recently traveled in an area where bird flu occurs, watch carefully for the following symptoms:
Stay informed: Keep up with the news and the latest warnings about bird flu.
The World Health Organization (WHO) estimates that 150 million birds have died due to Avian Influenza Virus, otherwise known as bird flu. In an effort to prevent the possible spread to humans, which has resulted in 129 deaths worldwide, infected poultry and wild fowl have been culled. Though for practical and economic reasons, killing infected poultry does not appear to be viable. The culling of wild migratory birds poses ethical and ecological questions as well, and the World Organization for Animal Health and the Food and Agriculture Organization of the United Nations has suggested the use of vaccinations as a method to prevent the spread of Avian Flu.
Two studies published in May by the Proceedings of the National Academy of Sciences of the United States of America show that it is possible to immunize poultry through the affordable and wide spread use of vaccinations for other viruses, in particular Newcastle Disease Virus.
Researchers in the United States at the Mount Sinai School of Medicine in New York created a dual-use vaccine against Newcastle disease and the H7N7 strain of bird flu. Chickens given the vaccine were completely immunized to Newcastle disease and had a 90 percent protection from that strain of bird flu. The vaccine is distributed in spray form or delivered in the drinking water of poultry.
In the United States alone, some 9 million birds are given Newcastle disease vaccines, says the German study. Existing vaccines for poultry have serious limitations, including difficult and labor-intensive delivery, and problems differentiating birds that have antibodies as a result of vaccination or from a previous infection of bird flu. Many countries do not import vaccinated poultry for this reason. The German study also proposes a method to differentiate between previously-infected birds and vaccinated birds.
Efforts are being made to vaccinate poultry stocks worldwide. The entire poultry population in China, for example is to be vaccinated, reports the American study.
The WHO is concerned about the possible mutation of the H5N1 strain of the bird flu virus into a form that would be easily transmitted among humans, starting a pandemic that could result in millions of deaths worldwide. According to the WHO’s fact sheet on bird flu, the first documented cases of human infection of the H5N1 strain occurred in Hong Kong in 1997. The current outbreaks since December 2003 infected 227 people in 10 countries. Currently infection has been a result of close contact with infected birds. No efficient human-to-human transmission of the virus is occurring, says the WHO.
Influenza pandemics are recurring events. The 20th century saw three pandemics; the Spanish Flu of 1918, and the Asian and Hong Kong influenzas of 1957 and 1963 respectively. The WHO notes that the Spanish flu killed an estimated 40 to 50 million people worldwide making it the deadliest disease event in human history.