Diseases and Viruses

[Anonymous No.7259067]

Hey /sci/, I come to you with a hypothetical question for a story I want to write.
A disease (or virus, I don't know exactly the definitions?) affects a few people but they are able to find a treatment or cure in time for some of them at least to survive.
The disease then mutates and affects others, much more seriously, and the treatment from before no longer works, but those that had it the first time around are now immune to it.
Does that make biological sense?

[Anonymous No.7259076]

Yes

[Anonymous No.7259091]

Goddamit, why don't you faggots stick to maths & engineering already ? Every time you guys try to talk about biology/medecine, you fail horribly.

>I don't know the difference between virus and disease

I mean, shit OP, even a 6 year-old is smarter than you

[Anonymous No.7259100]

eehhh. Think about influenza virus. A few strains pop up and infect people every year. Vaccines are made against those specific strains. People that get vaccinated are typically immune if those strains infect them. Mutations occur that change the surface antigens of the virus making it unrecognizable to the immune system, meaning people vaccinated for the original strains are not protected against these new strains.

Maybe if the particular surface antigen that was recognized in the original group remains unmutated than sure it could work.

[Anonymous No.7259116]

>>7259100
Also look up "antigenic drift" vs "antigenic shift" in terms of the influenza virus. Drift is responsible for the mild strains that occur each year. Antigenic shift is when say a virus from humans recombines with a virus from birds. These are typically much more virulent and responsible for epidemics so that might be a mechanism you could use for the increased virulence in group 2.

[Anonymous No.7259149]

>>7259091
Calm down mate I'm not a scientist. That's why I'm asking.

>>7259100
So if the virus mutates in such a way as that - so that people who had it before don't get it again - then does that also mean that the original vaccine/cure/treatment will still work against it?

[Anonymous No.7259188]

>>7259149
Depends on how the treatment works. Are you using a drug or a vaccine? And what is being targeted by the treatment vs what is being mutated on the pathogen?

Drugs work by directly affecting the pathogen. In the case of a virus they can work in a variety of ways, such as by disrupting some key part of the virus lifecycle (entry, attachment, replication etc). The virus can mutate causing the drug to have decreased effectiveness or be completely ineffective.

Vaccines work by training your immune system rather than interacting with the pathogen directly.

[Anonymous No.7259211]

>>7259188
Right, okay.

I don't have any fixed idea about whether it should be a drug or a vaccine, I just want it to make some scientific sense. So basically; a select few people (geographic region, I think) are exposed to a virus, get sick from it, but ultimately survive it (whether through treatment or just their base immune system) BUT they are still carrying it and it mutates, so it gets out and spreads, and this mutated sickness is more serious and kills everyone else - but those original people who had it first time around survive. Is that possible, in broad terms?

[Anonymous No.7259228]

>>7259211
Yea sure. Once again I suggest you read about antigenic shift. Seems like a perfect mechanism for what you want.

[Anonymous No.7259276]

>>7259228
Okay, great. Thanks for your help!

[Anonymous No.7259288]

>>7259067
>The disease then mutates and affects others, much more seriously, and the treatment from before no longer works, but those that had it the first time around are now immune to it.
>Does that make biological sense?
Yes, that's literally MRSA

Humans gain immunity through having antibodies specific to a pathogenic agent. As long as whatever epitope the Abs bind to doesn't mutate, then the human will always be immune to that serotype of the disease.

But something else can always mutate, such as it gains some anti-biotic resistant enzyme. That enzyme would not be outwardly present, so the epitopes would not change, but it would of course make the disease antibiotic resistant.

[Anonymous No.7259309]

>>7259288
What are the "Abs"? Are you saying that so long as the thing that mutates about the virus ISN'T the way that it reacts with the human immune system (or, the way the immune system has to fight it)?

[Anonymous No.7259329]

>>7259309
Core muscles. Bacteria have incredibly strong abs which allow them to swim against the bloodstream during periods of high bacteremia.

[Anonymous No.7259338]

>>7259309
>What are the "Abs"
Abs=antibodies
Ags=antigens
>>7259309
>Are you saying that so long as the thing that mutates about the virus ISN'T the way that it reacts with the human immune system (or, the way the immune system has to fight it)?
Yes. As long as the surface proteins/sugars etc aren't the part that changes, the human immune system will treat it the same way. If the thing that mutates is inside, it can become antibiotic resistant, but antibodies will still recognize it

[Anonymous No.7259344]

>>7259338
That is literally perfect news for my story. Thanks

[Anonymous No.7259371]

>>7259329

[Anonymous No.7259399]

>>7259067
Yes, memory cells in your immune system can remember strains of diseases and take them out early, which is how vaccines work. They give the memory cells the memory early and in a weaker way. As mentioned before, if it mutates to make itself different in certain ways so that it's no longer recognizable (typically by changing surface proteins), it won't work.

Pic related is Viruses; they're genetic code covered in proteins that sometimes look like D&D dice, and sometimes robots. Ebola is a virus, too, if you want it to look like that. And no, they aren't alive (but many people will argue on this subject, whether viruses are living or not, and there's no clear answer, so people are welcome to their opinions, and you can decide for yourself).

Your picture is bacteria. They're a bacillus strain, because they look like rods. There's also coccus, a sphere, and spirillum, a spiral.

>https://www.youtube.com/results?search_query=kurz+gesagt+immune+system
Watch the one on bacteria infection, and then any other immune system-related ones you want.

[Anonymous No.7259473]

>>7259399
If it were to be something you could have a natural immunity develop (or, survive it) to in the first instance, but then it mutate quickly into something deadly (but with the same surface proteins) would that be a virus, or a disease, most likely?

[Anonymous No.7259502]

>>7259473
viruses cause disease along with bacteria and a variety of other microorganisms. Disease is not an agent. Pathogens cause disease.

and yes that could be a virus.

[Anonymous No.7259504]

>>7259502
Okay great, thanks. Sorry to be so stupid.

[Anonymous No.7259518]

Sorry one more question - is antigenic shift (mixing with another strain of the same virus?) the only way that such a powerful change could occur in the virus over that short space of time?

[Anonymous No.7259539]

>>7259518
No. A random mutation could occur that increases the virulence of the pathogen, though that it pretty rare but possible.

[Anonymous No.7259618]

>>7259518
>>7259539
He's right in this instance. Coincubation of different influenza strains, a segmented virus, can lead to genetic shift. Drift is the gradual accumulation of mutations or stochastic assortment of alleles.

[Anonymous No.7260380]

>>7259618
Sorry, so are you saying that shift = when it happens quicly, and drift = when it happens slowly? And when it's a 'shift' rather than a 'drift', is it necessarily because it mixed with another strain, or can those mutations just happen anyway?

I'm sure you can tell I haven't studied biology since high school... I'm really sorry for these probably extremely stupid questions.

[Anonymous No.7260431]

>>7260380
http://www.cdc.gov/flu/about/viruses/change.htm?mobile=nocontent

Shift, as far as I know, is strictly due to incorporation of components from two distinct viral strains. Think of it as taking out the engine of one car and putting it in another.