Virus

[China Doll]

Morning All,

I hope you all had a good festive season.

I (and several others no doubt) have had a cold recently that is particularly evil. For a start I rarely if ever get colds so me coming down with it is unusual in the first place. However this strand appears almost flu like... tho not the flu as I've still been able to drag myself out of bed to live my normal life and I've been told that flu flatterns you for days.

Is there actually a mutant cold virus going round? Does it have a name? Is it true that no cold viruses are the same? If so, why is that? Is it true there is no cure for a virus? And if so, then what about things like HIV? Does that mean there will never be a cure for that? And how did viruses come about anyway? What actually are they?

Cheers
(Ever curious) China xx

[LazyGun]

Soooo many questions, China :)
1. What is a Virus and their origin ?. Ultramicroscopic infectious agent that replicates itself only within the cells of living hosts. In essence a piece of nucleic acid (organic replicating molecule), most commonly RNA but sometimes DNA. Their origin is difficult to ascertain, since unlike larger organisms they don't for example leave a fossil record. It is has been hypothesised that they are the living remnants of the enzyme that switched our replication system from RNA to DNA, and , in similar fashion to Darwins theories that all life is from a common ancestor, that viruses too all have a common, long distant ancestor.

2. Cold Viruses. I think there are thought to be approx. 200 viruses associated with the common cold. These viruses are broadly linked into "families" of viruses, but all can give the common symptoms of a cold when present in humans.

3. Cure for common cold viruses. Very difficult to come up with a cure for the cause rather than the symptom, since there are 200 or so, all of which will evolve/adapt/mutate. You would have to find a marker (protein present on the virus) that was common to all, but not present in humans in order to target any cure....and because there are so many, from several different families, and they are mutating all the time, this would be extremely difficult.
Secondly, you have to question the worth of such a thing... A cold is hardly life threatening after all ( although can be an extreme nuisance, I know), and the illness itself is of a very short life span.
Thirdly, treating the symptoms of a cold is probably a better use of resource/time/research etc in any event.
So, in answer to your question... no, its is unlikely that there will be a "cure" for the common cold any time soon.

ctd

[China Doll]

Ahem.... RNA? (Sorry)

[LazyGun]

ctd
4. Cure for HIV etc. Some viruses, due to their pathogenicity, are worth trying to find a cure for, and HIV would be an example. The best approach for cures would be either as a vaccine, which has an established track record ( think MMR etc), or drug. A vaccine relies on the bodies own immune system to defend the host and works by stimulating the immune system to produce defensive antibodies by introducing either dead virus ( or protein markers unique to the virus ) or attenuated "live" virus to the host. Unfortunately, HIV works by subverting said immune system, which does create problems. Additionally, as with other viruses, it does mutate... there are several major types of HIV doing the rounds now. The immune response is a complex beast, and the initial approach, which uses a common surface protein marker on the virus sheath as a target for antibodies stimulated by a vaccine has been lacklustre. Additional work is being done on the secondary immune response systems, but that is a much more complex animal, so don't hold your breathe.

Antiviral drugs have been shown to work, but these are cyto toxic and will also affect healthy cells, so they can have serious side effects in their own right. ( Think shotgun blast and innocent bystanders)

Hope this answers at least some of your curiosity China.

[LazyGun]

RNA = RiboNucleicAcid... a simpler form of DNA, which is the basic building block of life ( self replicating molecule)

[China Doll]

Gunner, you're a star.

Seems to answer everything... tho no doubt will make me think of some more questions in the future....

Thank you!

[LazyGun]

NPs China... I won't claim the answers are exhaustive, and there may be some errors in terminology... but hopefully it gives you a basic picture of what is going on. There are plenty of sites available for further reading if you are interested in refining your understanding :)