Question about Tamiflu

[shraby]

last year when the bird flu was prevalent in Asia, Tamiflu wasn't considered an effective vaccine against it. Why is it the vaccine of choice now? There was another vaccine that was better, it started with an R and was a 5 letter word. For the life of me, I can't remember the name of it. I watched the bird flu spread from Vietnam throughout the whole region by putting bird flu in google news and then sorting by date.
The consensus was that Tamiflu wasn't very effective.

[Bluebear]

1. Tamiflu is not a vaccine

But it is said to make the flu less severe if you take it when symptoms appear.

on edit- Is it Relenza you are thinking of?

[shraby]

7. Not Relenza, it was a shorter word.

[mike_c]

2. tamiflu isn't a vaccine, it's an anti-viral and it does help...

...to weaken the virus and give the body's immune system and infection response a chance to fight back. But Tamiflu does not in itself convey any immunity.

[donco6]

3. Tamiflu is not a vaccine.

It is a tool to fight viral infection. It is not specific to any virus, as a true vaccine is.

[MuseRider]

4. Relenza?

It might be that. These are not vaccines.

Edit to add http://www.fda.gov/cder/news/relenza/default.htm

[smoogatz]

5. Tamiflu isn't a vaccine

It's an intiviral drug--you take it when you start to have symptoms. It should be pretty effective against avian flu--or so I heard on Talk of the Nation Science Friday. Apparently there was another drug--whose name I forget--that worked pretty well, too, but the Chinese government ordered poultry farmers to put it in the water supply for their birds and the virus became resistant to it. I can't remember the name of that drug, or whether it starts with "r."

[drfresh]

13. The name is... amandatine

More Info:
http://discuss.agonist.org/yabbse/index.php?board=6;action=display;threadid=21748

[Citizen Jane]

6. This article sheds some light on things:

http://www.recombinomics.com/News/09170502/Tamiflu_Amantadine_Prevention.html

From that article...

"The emphasis on Tamiflu is due to the fact that the H5N1 isolated from patients in Vietnam and Thailand was amantadine resistant, so the only class of antivirals available was the neuramindase inhibitors, and only Tamiflu was readily available."

[NNadir]

8. Tamiflu is not a vaccine.

It is a neuramidase inhibitor which means that it is a drug for treatment rather than prevention.

The other drug is Relenza.

Neuramidase inhibitors work by preventing the virus from attaching to the cells it is going to infect. This attachment is mediated by a protein (neuramidase). Proteins typically have very specific three dimension geometry in the presence of binding agents.

Viruses evolve rather rapidly because billions of generations can take place in a single day and typically there is no mechanism for correcting transcription errors when their nucleic acids duplicate. (This is a reflection of their simplicity.) This allows for many variants, only a fraction of which must survive to give an infection. Mutants can have slightly different shapes of the three dimension proteins, and thus not all drugs are equally effective against all strains. Moreover, the drugs themselves provide what we call selection pressure, i.e. the only viruses that succeed are those that have mutations that make the drugs ineffective. (This same effect takes place with bacteria and antibiotics, but it is slower because bacteria breed more slowly.)

[NNadir]

9. We all had the same thought at the same time.

[donco6]

10. Ha! yes.

I think we all hit the post button simultaneously. There wasn't anything when I started.

[Carolab]

11. HAD to be Relenza. Here is more on this discussion.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=102x1837150#1838010

[LastDemocratInSC]

12. H5N1 avian flu is becoming resistant to Tamiflu

H5 = type 5 hemagglutin (15 basic types)
N1 = type 1 neuraminidase (9 basic types)

Both are proteins on the surface of the virus. The hemagglutin protein lets the virus invade the cell; neuraminidase lets new viruses exit from the cell once they have been created.

Tamiflu works by inhibiting the action of neuraminidase. The virus can invade cells and reproduce but has trouble getting the new viruses back out of the cell and into circulation. As a result, an infected person's viral load may be lower than it would be without Tamiflu, but the infection is still able to progress. It's like this: Would you prefer to be beaten by 1000 baseball bats or only 900?