05-11-2009 / Fluvirin – Fighting Against Influenza
04-30-2009 / Fluzone For Children
04-14-2009 / Flu Vaccines And Protein Chemistry
04-10-2009 / X Ray, Viral Structure And Flu Vaccines.
04-07-2009 / The History Of Influenza
04-06-2009 / Flu Vaccine Contamination And Quality Control
03-22-2009 / Egg Allergies And Flu Vaccines
03-12-2009 / Australian Discovery May Improve Existing Vaccines
03-06-2009 / How Humidity Affects Flu Outbreaks
03-05-2009 / Preservative-Free Flu Shots
03-04-2009 / Flu Strains Developing Resistance to Tamiflu
03-03-2009 / The History Of Influenza
02-23-2009 / Preservative-Free Flu Vaccines
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The media attention given to influenza has clothed this disease in the fabric of modernity. But influenza is, in fact, a very old disease that dates back thousands of years and varies in lethality from year to year and outbreak to outbreak.
In ancient Greece, Hippocrates described the symptoms of flu roughly 2400 years ago. For historical events such as these, we primarily have descriptions of symptoms rather than accurate diagnoses or demographic data. This makes it hard to accurately pinpoint ancient flu pandemics. One of the earliest records of an outbreak that can be linked to influenza was in 1580. It began in Russia and ultimately spread to Europe by way of Africa. One of the more virulent strains, this influenza killed 8,000 people in the city of Rome alone. Many villages in Spain were totally decimated.
Pandemics seem to hit about every century. There were periodic outbreaks in the 17th and 18th centuries. The pandemic of 1830 was especially widespread. It was also particularly infectious, and one out of four people exposed, or 25%, contracted the disease after exposure.
But the most infamous of all influenza outbreaks was the pandemic of 1918. Estimates for the number killed in this outbreak were between 20 and 100 million people. The wide range in the estimate is due to the global nature of this outbreak. This outbreak reached far flung Pacific Islands and the Arctic.
Not only did this strain of influenza have an extremely high infection rate—over 50% of people exposed contracted the disease—but the symptoms were especially severe. Hemorrhaging from the mouth, nose and intestines were common, as were hemorrhages under the skin. A majority of deaths were from secondary infections like pneumonia, but the virus killed directly with massive bleeding and swelling.
Another unusual feature was that the highest mortality rate was among young, otherwise healthy, adults. This was linked to a cytokine storm, which is a condition where the normal antibody/cytokine cascade is not stopped by the body’s own processes. It is as if the body over responds to the contagious agent, making so many antibodies that they begin to harm the body. Say this happens in the lungs. The lungs will fill with fluid and suffocate the patient before the virus can kill the patient.
Having established that the 1918 pandemic was bad, just how bad was it? It is estimated that between 2.5% or more of the entire world’s population was killed. To put in another way, in the first 25 years of the AIDS epidemic, 25 million people died. In 1918, over 25 million died in 25 weeks.
It has been reported that a large batch of seasonal flu vaccine which was to have been delivered and used in 18 countries in Europe has been found to have been infected with the deadly avian flu virus in live form. Fortunately, this was discovered before anyone was in danger. But if this problem had not been found as quickly as it was and these vaccines had been distributed and administered to patients, an avian flu pandemic could have begun, and the death toll could have numbered into hundreds of thousands.
An investigation is under way at the research facility in Austria. Baxter International, the pharmaceutical company who owns the facility where the problem occurred, has issued a statement confirming that a batch of flu vaccine did contain the live avian flu virus designated as H5N1.
A researcher discovered the lethal contamination when laboratory animals that he had injected with the flu vaccine suddenly took ill or died. The avian virus will become lethal when it is mixed with the usual flu virus found in the flu vaccines. This process known as re-assortment, and is exactly what public health organizations are afraid may happen in the wild. The laboratory created the perfect storm of conditions in a test tube.
It is crucial to note that we are not talking about a simple mistake, certainly not one to be buried on the back pages of the Internet. This could have been a world threatening, black plague level event here. A lab mistake created the very thing that we are trying to avoid. As frightening as it is that we dodged a bullet, it was a successful dodge. While the researchers lose points for getting a bit too close to mad scientist tech, the screening and security procedures get high marks.
This lab had the dangerous avian flu virus for the simple reason that they are engaged in research to head off any epidemic that might be caused by that virus. The thing to take home here is that there are layers upon layers of testing and control on every vial of vaccine. The tracking and quality control in a reputable and well run company is something on which we can rely.
Quality controls are a big part of flu vaccine production, as well as a mandated part of manufacturing in most, if not all, of the industrialized world. Most of the problems that are discovered are not of this magnitude, or have the potential to be so deadly. But in looking for the small mistakes, the large ones tend to get caught. And for that we should be thankful.
The group with the highest rate of flu in Australia is children under five. In fact, recent demographic studies have shown that children in this group are more frequently hospitalized for the flu than they are for any other disease which can be prevented by vaccine. Almost 1500 children in this age group are admitted each year to the hospital with the flu. Last year, six children died as result of the flu.
With flu season set to begin soon in Australia, experts are encouraging parents to have their children immunized. Professor Robert Booy is director of research at the National Centre for Immunization Research and Surveillance, Children's Hospital Westmead. He urges parents to not only vaccinate their children, but to be familiar with flu symptoms, which in young children include a high fever and being irritable.
“Some young children with influenza can look so unwell when they arrive at hospital that a spinal tap – otherwise known as a lumbar puncture – is performed to rule out meningitis,” Booy said. This is serious and often painful procedure. “Much of this might be prevented if children were vaccinated against influenza each year. Children are one of the main spreaders of influenza, particularly within households. Therefore vaccination is not only important to protect the health of the child, but also because of the key role they play in transmission, particularly if they are in contact with at-risk people or older adults.”
To further study the effects of children and the flu, researchers are conducting a trial on infants in 40 childcare centers located in Sydney. One of the goals of this research will be to determine if having infants and young children immunized against the flu makes a difference in how many of their parents get the flu. "So the question we've asked is: can we vaccinate the children and observe a benefit not only in them but a secondary benefit in their parents," Booy said.
This new trial is expected to show even greater benefit from the humble flu vaccine.
The majority of flu vaccines are made using processes that employ fertilized hen eggs. This process of manufacturing causes the vaccines to pick up small amounts of egg proteins. Even the nasal mist flu vaccine has as much or more egg protein as the injectable variety.
For most people, this is no problem. The majority of us pick up hundreds of times more egg protein from our diet than in a flu shot. Even excluding the obvious source, eggs, we get exposed to egg proteins from baked goods or foods processed with eggs on a regular basis. But there is a small, yet real section of the population that has an allergy to eggs. For those individuals, the flu shot can be a serious problem.
This is not a matter of one manufacturer against another: the fertilized hen's egg method is used throughout the vaccine industry. There are some different vaccine development methods on the horizon, however, that will use bacteria that have been genetically engineered to make flu vaccines. But until that day, the egg method and the egg protein in flu vaccines are here to stay.
The amount of egg protein varies from one vaccine manufacturer to another. If you are concerned about allergic reactions, you should talk with your doctor and request a vaccine with the least egg protein available. A skin test to determine whether or not you will have an allergic reaction to the vaccine is a good idea before getting a flu shot. If it is determined that you can have the vaccine, the best course of action is not to leave the medical facility for at least 30 minutes afterwards, so that the staff can observe you and respond promptly to any distress that you may have.
If your allergies are too severe for vaccination, there’s still a way to minimize the effects of the vaccine. You can have the vaccine administered in small doses over a period of time, instead of getting the full dose in one sitting. This, of course, should also take place under close medical supervision. In the cases of the most severe egg allergies, it will probably be safer to not have the vaccine at all and take antiviral medications if you are exposed to or catch the flu.
In a study published this week in the Proceedings of the National Academy of Science, Australian researchers announced a discovery that may not only improve on existing influenza vaccines, it may also finally offer the promise of the much hoped for bird flu vaccine.
In the body, we produce T-cells. These T-cells play an essential role in our immune system: they find and destroy infected cells. These killer cells help us rid our bodies of infections. To make us better able to fight off the flu, a vaccine would ideally increase T-cell activity, helping the cells target and destroy virus-infected cells. "Unfortunately, current influenza vaccines are poor at inducing killer T-cell immunity," according to Stephen Turner, lead author of the study, and member of the microbiology and immunology department at the University of Melbourne. "Therefore,” he said, “we wanted to see if we could improve the current vaccine formulation to induce killer T-cells after vaccination."
In the study, a compound known to increase immunity was added to the flu vaccine by Turner and his fellow researchers. Turner says, “The addition of this compound promoted significant generation of potent killer T- cell immunity and provided protection from infection. The significance of these findings is that, rather than having to design a new vaccine altogether, we can improve current flu vaccines by adding this potent immune modulator."
According to Turner, after appropriate clinical testing has been completed, this compound could take its place in existing vaccines only five years from now.
This is a new approach to flu vaccine development. Most changes in the flu vaccine revolve around targeting new or different strains of the flu, anticipating which will be most problematic in the upcoming season. This is one of the first advancements designed to increase the functioning of the immune system of the patient who contracts the flu, regardless of strain contracted. While no vaccine is yet perfect, they are still important for preventing complications from the flu, preventing infection from certain strains of the flu, and especially for protecting individuals who are particularly vulnerable to the flu or its complications.
Vaccine Preparation Starts for 2009-2010 Season
It takes flu vaccine manufacturers about eight months to develop and produce the vaccine for the upcoming flu season. About 100 million doses of the flu vaccine are needed each fall. The vaccine changes each year because the virus is constantly mutating and producing new strains. Typically, only one or two strains in the vaccine are changed each year. For the upcoming season, however, three new flu strains will be included.
The U.S. Food and Drug Administration (FDA) hopes this will avoid problems that occurred with this year's vaccine. This year has seen widespread and regional flu activity. This is largely attributed to infections caused by flu strains not included in the current vaccine, and by strains that have become resistant to antiviral medication. The most common virus strain in the U.S. at the present time is influenza type A H3N2. This strain is not in the current vaccine, which also does not protect well against influenza type B. Several influenza type A viruses are showing resistance to Tamiflu, a popular antiviral drug, as well.
Protection against influenza type A H3N2 will be included in the vaccine for the 2009-2010 season, following a recommendation from the World Health Organization (WHO). The FDA is also recommending that the vaccine protect against two additional influenza type A strains: a H3N2 flu knows as Brisbane/10, and a H1N1 flu known as Brisbane/59. A influenza type B/Florida strain will also be included.
According to infectious disease expert Dr. Peter C. Welch, “Part of the issue is that the vaccine which was produced this year is not the most effective vaccine that we've had for influenza. Although these [vaccine development choices] are educated guesses, they clearly are guesses. Sometimes, they guess right. Sometimes, they guess wrong. This year, they didn't guess well. Sixteen out of the last 19 years they have guessed pretty well." Dr. Welch is with Northern Westchester Hospital, Mt. Kisco, New York.
Despite the fact that this year's vaccine may not be the best match for the flu strains that are circulating, the CDC still recommends that people get the vaccine. The vaccine can reduce the risk of complications related to the flu, and still provides partial protection, both of which are especially important for people who are at greater risk.
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