Skip to comments.New study raises the possibility that some antiviral drugs could make diseases worse
Posted on 01/13/2010 3:01:23 PM PST by decimon
Research published in the journal Genetics suggests that mutagenic drugs designed to kill viruses may make them stronger
As the flu season continues in full-swing, most people can appreciate the need for drugs that stop viruses after they take hold in the body. Despite this serious need for new drugs, a team of researchers from the University of Texas at Austin raise serious concerns about an emerging strategy for stopping viral infections. According to their research report appearing in the January 2010 issue of the journal GENETICS, medications that cause viruses to die off by forcing their nucleic acid to mutate rapidly might actually, in some instances, cause them to emerge from the process stronger, perhaps even more virulent than before drug treatment.
"This work questions whether the practice of 'lethal mutagenesis' of viruses works as predicted," said Jim Bull, Ph.D., a researcher involved in the study from the Institute for Cellular and Molecular Biology at the University of Texas at Austin. "It remains to be seen whether an elevated mutation rate that does not cause rapid viral extinction enhances treatment or may instead thwart treatment by enhancing viral evolution." Bull's research collaborators included Rachael Springman, Thomas Keller, and Ian Molineux from the same institution.
Scientists tested the model of viral evolution at high mutation rates by growing a DNA virus in the presence of a mutagenic agent. The current accepted model predicted that the virus would not be able to handle the high mutation rates and would eventually die off. However, this study proved the model false, as the virus actually increased its fitness at elevated mutation rates. During this study, scientists found molecular evidence that rapid mutations had two effects. The first effect of most mutations, which was expected, was that they killed or weakened the virus. The second effect of some mutations, however, was that they actually helped the virus adapt and thrive. Although the researchers did not question that extremely high mutation will lead to viral extinction on the whole, this discovery raises the specter that forcing viruses to undergo rapid mutations could, if the mutation rate is not high enough, accidentally lead to well-adapted "super viruses."
"This study should raise more than a few eyebrows over this approach to stopping viruses," said Mark Johnston, Editor-in-Chief of the journal GENETICS, "because the last thing anyone wants to do is make a bad situation worse. More work must be done to determine the actual likelihood of this approach yielding a super virus, knowing that it is possible is a big help in preventing what could be a very big problem."
DETAILS: R. Springman, T. Keller, I. J. Molineux, and J. J. Bull Evolution at a High Imposed Mutation Rate: Adaptation Obscures the Load in Phage T7 Genetics, Jan 2010; 184: 221 - 232.
Since 1916, GENETICS has covered high quality, original research on a range of topics bearing on inheritance, including population and evolutionary genetics, complex traits, developmental and behavioral genetics, cellular genetics, gene expression, genome integrity and transmission, and genome and systems biology. GENETICS, the peer-reviewed, peer-edited journal of the Genetics Society of America is one of the world's most cited journals in genetics and heredity.
From a purely Darwiian standpoint, a really well-adapted virus causes little or no ill effect on its host.
I hate sloppy scietific writing.
Yeah, it does a virus no good to kill you, as it then dies.
The really nasty versions of the Plague ceased to exist because, well. . .
The experience with Tamiflu during the Air Force Academy H1N1 outbreak in July seems to indicate that it doesn’t shorten duration of illness or decrease infectivity. I discussed that with another Critical Care doc and his response was, “Then what the F*** are we doing?”
I think that means an ill-behaved virus dies out for killing its hosts.
Be kind to bacteria/viruses. It just mihgt save your life.
Evolution of living organisms occurs through natural selection of genetic variation.
Thus the selective pressure of the mutagen and the increased genetic variation caused by the mutagen may well give rise to a genetic variation with beneficial (for the virus) attributes.
But as Jewbacca points out, the most beneficial variation for a virus is where they are highly infectious but cause little or no detrimental outcomes to the host species.
We had the once every 5-7yr flu/cold virus this year.
Just rode it out (bit***ng) all the way.
Having other chronic medical care issues we deal with quite well it is amazing how a cold/flu virus can turn one into a whining baby.
I swear I can feel every part of the body it visits throughout the course and then there is the re-boot/relapse that slaps ya up side the head before it goes into regression or what ever it does.
We were not in a position to run to town and get an antiviral med and did fine on plenty of fluids/rest ect...
I often ponder so much of the stuff pharma companies put out under the guise of science as just a way to earn profits.
The one OTC med KV uses on a regular basis as a quad with spastic lungs is plain Mucinex (brand name for the g word) to keep lung fossils (my name) from forming IOW keep secreations clear.
We have tylonal and advil in the medicine cabinet but rarely have a need to use.
Personally as I age I find that the old Grammas Kitchen cures much better.
Dont misunderstand if we were in need of antibiotics we would use them or any other pharm med.
Just not a need IMO for bouts of viruses, stress headaches, allergies and other non lethal illnesses.
And home remedies out of the cupboard wont set cha back $$$$ such as the OTC remedies.
Thanks for the ping!
You’re welcome, Alamo-Girl!
Thanks for sending the ping.
Thanks for the heads-up!
Simply put, medicine has long held the idea that the way to defeat a pathogenic disease is by killing it. But this invokes natural selection, as these pathogens don’t want to be killed. So it adapts to protect itself.
A better way is to interfere with the mechanisms the pathogens use to invade and replicate. This makes it much more difficult for natural selection to create an organism that can get by such defenses.
I see that nobody seemed to have learned much from anti-biotics.
That should have been the first thing that they considered that anti-viral resistant forms of viruses would crop up just as the anti-biotic resistant strains of bacteria did and so not prescribed stuff like Tamiflu prophylactically.
My daughter came down with the swine flu (they could trace the transmission from someone who was tested and confirmed to have it) and my PCP wrote out a prescription for everyone in the family. She took it because she caught it within the first day or so. She knew she had been exposed so when she started showing symptoms, it was no surprise. The rest of us were exposed as well and we THINK that my youngest daughter had it as well, but aren’t sure. She wasn’t sick enough.
The article isn’t exactly correct that it would make the viruses stronger. What it would do is that if stronger strains became anti-viral resistant, they would be harder to treat and more prevalent because they couldn’t be treated, and so be more likely to kill.
BTW, did you notice that the swine flu just kind of died out on its own? It was just about the time my oldest caught it, about Oct, IIRC, and then that was about the last you heard about it. I haven’t even heard of the regular flu being much of an issue.
Just so everyone knows, you can find the Mucinex off brands MUCH cheaper about anywhere. You just need to be aware that Mucinex is 600 mg tablets and the generics are 400.
My allergist prescribes 1,200 mg twice a day for sinus congestion and says (confirmed by a pharmacist) that it is very safe even at those doses; that guaifenesin is a very safe, very old medication. What I like about guaifenesin over Sudafed, is that it does the job without making you feel like a space cadet. It does not have the side effects that Sudafed does.
That seems to be the norm for flus. They run their course according to their makeup and not our arbitrary time lines.
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