Swine flu insights
Some of the brightest luminaries of our time give in-depth expositions of pandemic swine flu. With the help of Big Think’s pandemics experts, we’ve sorted through the chaos and put together a list of little-known facts about H1N1.
While the Centers for Disease Control calculate that the number of deaths over the next two years could range from 90,000 to several hundred thousand, the World Health Organization believes H1N1 is still in the “early stages” of a new pandemic. They estimate that 2 billion people (one-third of the world’s population) could be infected over the next two years.
Chairman and professor of the department of microbiology at Mt. Sinai Medical Center in New York, Peter Palese, discusses the influenza viruses and the disease which is caused by these viruses.
The virus is very, very small. A cell which is infected by this virus is probably as large as the Empire State Building. So this is a very small virus which can within 8 hours, infect us all and kill this Empire State Building and make about a hundred thousand new virus particles.
In humans, we know that there is influenza every season in the Northern Hemisphere from November to March. And also many people know that a hallmark of the virus is that it changes. Influenza viruses have circulated since the last century. We know about the 1918 virus, which caused the deaths of three quarter of a million people over a three month period in the US alone. This virus was also replaced in 1957 by a separate virus, and then in 1968, a new sub-type emerged, an H3 virus which, is actually still with us in 2009. In addition, in 1977 there was another H1 virus reappearing.
In 2009, there are H1 and H3 viruses circulating. Vaccines, which are very helpful, are not perfect but they are a very important way of preventing influenza. Unfortunately influenza also changes within one of these H1 or H2 or H3; there are constantly changes going on. That means that the vaccines have to be changed as well.
For the 2009/2010 season, there is a vaccine formulation now which is being produced by manufacturers and there is actually a new strand and new influenza B virus. So for the season which will start in November of 2009, this is the new vaccine formulation.
In the end of March of this year [2009], a new virus that belongs to this H1 group emerged, and it is known as either the new swine virus, or the Mexican virus, or as the Mexicans call it, the American virus, the California virus. So clearly this is a new virus and “I think the CDC [Centers for Disease Control] decided to just call it a new H1N1.”
“The virus is actually quite active. A couple of weeks ago, 105 countries have already confirmed this novel H1N1 virus.”
Older people are less affected by H1N1 because they’ve had it – many times. Dr. Peter Palese says people over the age of 55 have built up an immunity against swine flu. Why? The viruses that circulated 50 years ago are more closely related to the swine-origin H1N1 viruses than are present day seasonal H1N1 viruses. So exposure to the earlier viruses gives them protection.
We all have some kind of protection against this new pandemic swine. In the case of this H1N1, there is some evidence that there is some cross protection.
Ecologist and evolutionary biologist Michael Worobey says for the emergence of the influenza virus in general there is a swine lineage, and there is a bird lineage. And these are the major players in the emergence of human influenza.Most of the genes of this new variant come from pigs.
Viruses evolve so quickly that you can actually see evolution happen, not just on the time frame of years, but in the time frame of weeks.
What is the timing on the ancestor of the virus once it jumped into humans? When that jump took place what’s the most closely related species for each gene? It’s actually a pig virus.
What is seen when you go gene by gene is that, even for the ones that are ultimately an avian or human origin, they traveled through pigs. In each case, we find that there’s been a timeline of about 10 years where this virus has been in pigs but has gone totally unnoticed – which says something about our surveillance.
For the human outbreak, there’s a timeline about somewhere around October to December of last year [2008] that the virus was probably in humans. So it took several months to actually spread to the point where the tip of the iceberg became apparent to us.
“We think what’s going on there is once this virus jumps into humans, it actually started evolving at a more rapid phase, and it looks like it goes at about 1.5 times the rate that it evolves in pigs.”
“Because the swine virus is very similar to other H1 viruses which are circulating, there are no real technical challenges to make a vaccine, and companies are really able to make large quantities of this new vaccine.”
There’s a further goal in learning what’s going on in veterinary medicine and agriculture, as that interplay with humans is what over the last several decades has brought us disease after new disease. Dr Michael Worobey thinks this epidemic has taught us that we could do a lot more for surveillance, not only in humans but also in animals. And just being aware that there is a new subtype of virus circulating somewhere in the world, four months earlier than we were in this case, would set us up so much better to try that, isolate it, or at very least prepare a vaccine for it.
“I think it’s reasonable to look into the future and see a time when doctors routinely take swabs from patients who might have influenza, when abattoir semblance samples, from a large sample of animals, and they go to somewhere, or multiple places, and if there’s any virus, we will detect it before it gets to the stage it is now.”
Pregnant women face a dangerous dilemma: they are at the highest risk of becoming ill from swine flu, but nobody in that group will have a chance to test the vaccine. Why? Testing any type of vaccine or drug on pregnant women (and their babies) poses an ethical dilemma – and always has. Dr. Ruth Faden, Executive Director of the Berman Institute of Bioethics at Johns Hopkins, says, “Medicine is flying blind in many cases. Many of the drugs that women take in pregnancy because they’re seriously ill, we just have no evidence what the impact is for them or what the impact will be for their babies.”
This information was taken from www.bigthink.com
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here is a link to a report at CNN that shills for the meat industry and shows what bad reporting looks like
http://pagingdrgupta.blogs.cnn.com/2009/09/11/stop-calling-it-swine-flu
good work momento24