My amature Question !

[Commander]

I believe one of the terminating ILLNESS for Human Beings particularly in their OLD AGE is the very Popular COLD and its Manifestations !

 

I understand COLD is a Virus !

 

Don't we require to channelize all our energy to FIGHT THIS VIRUS with concentrated Research and Scientific Efforts !

 

Something like a VACCINE or CURE to Remove this Virus from Earth or at least from Human Beings !

 

Just Brainstorming here !

[Function]

Are you speaking of a "common cold"?

 

If so, it's not as easy as you'd want it to be.

 

Let me try to explain it: the common cold is evoked in most cases by a virus of which its genome consists of RNA. Some may be evoked by an adenovirus, which has DNA.

 

(I could get further into detail about single stranded (positively vs. negatively oriented) vs. double stranded but I won't because that just isn't so important right now.)

 

Most DNA viruses replicate in host cell nuclei and use host polymerase to do so. Fine, no problem. You could theoretically think of a vaccine. One big exception: variola (smallpox) which carries its own polymerase in its way too large genome.

 

But a vaccine against DNA viruses (I can only think of a vaccine against hepatitis B virus) won't eradicate the common cold, since there are just too many subtypes of the adenoviruses (and the HBV vaccine works by binding antibodies to the surface of HBV, we call them HbS-Ab: Hepatitis b surface antibodies). Other vaccines may work by evoking immune response against a specific toxine produced by the virus ...

 

So if you already consider variation in DNA viruses ...

 

RNA viruses are much worse. RNA viruses are obligated to carry their own RNA polymerase (reason for that is quite obvious, given that we all have DNA, and not just RNA in our chromosomes, so we use a polymerase fit for that) and perform transcription and replication in the cytoplasm with their own RNA polymerase (again one big exception: influenza replicates in the nucleus).

Now, the problem with their own RNA polymerase, is that it makes lots of mistakes. And a mistake in replication, transcription, ... results in a mutation.

 

And you guessed it, mutation results in subtypes.

 

So RNA viruses have tons of more subtypes than DNA viruses, and since the common cold is most commonly provoked by RNA viruses, finding a cure against all viruses that cause common cold is not going to happen.

Edited January 16, 2017 by Function

[Daecon]

Aren't there like 100 different viruses that cause the common cold?

[CharonY]

I would also like to comment that while mutation rates differ between DNA and RNA viruses (though there is quite a bit of overlap), it is not necessarily the only or main determinant of vaccine development (though it makes it certainly makes it more difficult). Rather, it depends quite a bit on whether there are conserved features necessary for the infection process that can be targeted (or, if you will, how many serotypes there are around).

There are, of course, successfull vaccines for both classes, though pipelines of development can be quite different.

 

Edit: Somehow I copied a line from a different comment into this one here, my apologies.

Edited January 16, 2017 by CharonY

[Strange]

I believe one of the terminating ILLNESS for Human Beings particularly in their OLD AGE is the very Popular COLD and its Manifestations !

 

 

Flu, maybe. Pneumonia, very possibly. But the common cold? I suspect anyone who is killed by a cold, is so ill that they were not going to live long anyway.

[Commander]

Are you speaking of a "common cold"?

 

If so, it's not as easy as you'd want it to be.

 

Let me try to explain it: the common cold is evoked in most cases by a virus of which its genome consists of RNA. Some may be evoked by an adenovirus, which has DNA.

 

(I could get further into detail about single stranded (positively vs. negatively oriented) vs. double stranded but I won't because that just isn't so important right now.)

 

Most DNA viruses replicate in host cell nuclei and use host polymerase to do so. Fine, no problem. You could theoretically think of a vaccine. One big exception: variola (smallpox) which carries its own polymerase in its way too large genome.

 

But a vaccine against DNA viruses (I can only think of a vaccine against hepatitis B virus) won't eradicate the common cold, since there are just too many subtypes of the adenoviruses (and the HBV vaccine works by binding antibodies to the surface of HBV, we call them HbS-Ab: Hepatitis b surface antibodies). Other vaccines may work by evoking immune response against a specific toxine produced by the virus ...

 

So if you already consider variation in DNA viruses ...

 

RNA viruses are much worse. RNA viruses are obligated to carry their own RNA polymerase (reason for that is quite obvious, given that we all have DNA, and not just RNA in our chromosomes, so we use a polymerase fit for that) and perform transcription and replication in the cytoplasm with their own RNA polymerase (again one big exception: influenza replicates in the nucleus).

Now, the problem with their own RNA polymerase, is that it makes lots of mistakes. And a mistake in replication, transcription, ... results in a mutation.

 

And you guessed it, mutation results in subtypes.

 

So RNA viruses have tons of more subtypes than DNA viruses, and since the common cold is most commonly provoked by RNA viruses, finding a cure against all viruses that cause common cold is not going to happen.

 

Hi Thank you so much for throwing light and knowledge on the subject ! I am sure it will be a tough proposition having defeated many attempts !

 

Yes I did refer to the Common Cold !

 

 

Flu, maybe. Pneumonia, very possibly. But the common cold? I suspect anyone who is killed by a cold, is so ill that they were not going to live long anyway.

 

I do think that those are further development to Cold. Like if I have a severe Cold but still take a headbath I might land up with pneumonia ! Flu is different though ! My experience suggests that those who are not attacked by any severe category disease too are unable to face COMMON CHRONIC COLD in old age ! Whether in Hot or cold climate !

 

Cold & nose blockage etc leading to severe breathing problems etc.

Edited January 16, 2017 by Commander

[Function]

I do think that those are further development to Cold. Like if I have a severe Cold but still take a headbath I might land up with pneumonia ! Flu is different though !

 

How is flu different? The common cold may be caused by the influenza virus, which also happens to cause "the flu". Any virus inducing the cold, the flu, ... might have a pneumonia ready for you, given that they might damage lung cells and epithelium, leaving a great opportunity for other pathogens (bacteria) to colonize and infect you (surinfection).

[Commander]

 

How is flu different? The common cold may be caused by the influenza virus, which also happens to cause "the flu". Any virus inducing the cold, the flu, ... might have a pneumonia ready for you, given that they might damage lung cells and epithelium, leaving a great opportunity for other pathogens (bacteria) to colonize and infect you (surinfection).

 

Oh OK then that too comes under the same category ! Strange pl note !

[Function]

 

Oh OK then that too comes under the same category ! Strange pl note !

 

Doesn't mean there is no difference, though there is a gradient; influenza can actively lyse cells by messing with their replicational systems in the nucleus, so of course influenza is somewhat worse. But any virus that affects the respiratory system might theoretically provoke a bacterial surinfection when the epithelium is damaged enough

[CharonY]

One should also note that frequent or chronic illness espcially by relatively harmless viruses can be an indicator of issues with the immune system. As others have noted, there are numerous viruses that elicit the typical cold symptoms, with the most common one being a picornavirus. As of yet there is no known direct link with actually being exposed to cold, except that being exposed to higher ambient temperature seems to lessen inflammation (in mice).

[DrmDoc]

One should also note that frequent or chronic illness espcially by relatively harmless viruses can be an indicator of issues with the immune system. As others have noted, there are numerous viruses that elicit the typical cold symptoms, with the most common one being a picornavirus. As of yet there is no known direct link with actually being exposed to cold, except that being exposed to higher ambient temperature seems to lessen inflammation (in mice).

According to this 2014 study, also reported in this New York Times article, "...cooler temperatures can enable replication of the common cold virus, at least in part, by diminishing antiviral immune responses." Replication occurred in the lungs and nasal cavities of test animals at lower body temperatures that could be caused by lower ambient temperatures, which seems to suggest a link between exposure to cold weather and certain viruses.

[CharonY]

That is a bit of extrapolation of the in vitro study and there is actually one major issue with the finding that the authors do not address. If airway cells are able to express interferon genes as a means of defense, why would there be a mechanism that down-regulates it at lower temperatures and thus reduces the effectiveness specifically in the area where it would be most critical?

 

There actually has been a hypothesis that it is specifically to allow viruses to grow there, in order to be able to raise antibodies before they reach sites where the virus can do more harm. But again, these are just assumptions at this point, requiring actual in vivo data.

 

There are also newer studies that, again in vitro suggest that binding of viruses may be more efficient under low temperatures. But the relevance in vivo is still unclear.

[DrmDoc]

I agree; unfortunately, extrapolation is a norm for most animal studies. As I understand the 2014 study, lower temperatures did produce "a less efficient antiviral defense response of infected cells". If this is true, then my next question would likely be how does cold weather lower our antiviral defenses rather than why would there be a mechanism for that lower response in cold weather? A down-regulation of our defenses in cold weather certainly seems a counterintuitive response unless the response mechanisms are specifically keyed to tropical or warm weather viruses, which might be more plentiful than cold weather types.

Edited January 16, 2017 by DrmDoc

[CharonY]

Iirc many cold-like viral infections are more common in tropical areas.

[Commander]

Thank you folks for all your inputs !