Is It Possible For A Covid Variant To Get Weaker As It Mutates?......

[global1]

Could a Covid mutant turn on itself and basically render it harmless?

I don't know if these questions were ever asked or ever addressed.

[sabbat hunter]

1. It is possible

that one variant can be more transmissible, but cause weaker symptoms. Completely harmless is unlikely.

[Bernardo de La Paz]

25. Not only possible, but it is the dominant theory. That in a pandemic mutants tend to be weaker. nt

[Tree-Hugger]

2. Yes

That is often - but not always - a natural progression fir some viruses. If a virus kills most of it's hosts, it can't spread. It's an evolutionary benefit for a virus to mutate to become much more transmissible and less lethal.

[Volaris]

9. Agree.

Most Ebola outbreaks are at least partially self-containing, because that virus is so very nasty that it kills its host before it can be transmitted to the next village over.

[enki23]

10. killing the host is not necessarily a negative for transmission.

https://en.wikipedia.org/wiki/Optimal_virulence

There is no simpler answer to these questions. Unfortunately, it's clear there's no good reason to think there is evolutionary pressure to become less virulent over time.

[TygrBright]

3. Be specific about "weaker"...

Yes, it is possible for the virus to mutate in a "less virulent" direction, making it less likely to kill its host. That would be a pro-survival mutation for the virus.

However, it's also possible for the virus to mutate in a "way more easily transmissible" direction, in several ways, making it more likely to reproduce, also a pro-survival mutation for the virus.

So it depends on what you mean by "weaker."

helpfully,
Bright

[VMA131Marine]

4. Viruses tend to evolve toward weaker strains

Because a virus can’t replicate if it kills it’s host. Natural selection will favour more transmissible but weaker strains.

[DenaliDemocrat]

5. The natural trend should be

Less lethal but more contagious

[Ms. Toad]

6. It's been talked about -

and was one of the surprises with Delta.

Generally as a virus gets more transmissible it gets weaker.

To survive (the viruses' ultimate goal), it can't kill off its hosts before they can infect enough others to keep it going. So if it infects more/faster, it needs to lessen its impact on the host so the host survives to infect more.

[roamer65]

7. Natural selection

The mutants which are more transmissible and less virulent are favored.

[Voltaire2]

8. Increased lethality does not

necessarily help the virus propagate, in fact if the host dies too soon, the spread factor diminishes. This is one reason why Ebola, so far, hasn’t broken out of a fairly limited region of Africa.

So sure, lethality can diminish in mutations and diminished lethality might be advantageous.

[viva la]

11. That happens with viruses-- lots of flu strains just die out-

And what sometimes happens is the weaker but more contagious strain kind of overcomes the deadlier one.

Or== like the Spanish Flu, the virulent strain kills off the most susceptible, and gives immunity to most people, and just becomes less effective.

[bearsfootball516]

12. Pretty sure it is, yeah.

That's how the bubonic plague died out in Europe.

Of course, it killed 1/3rd of the population first, so I wouldn't advise going that route.

[viva la]

18. Fortunately, we have a vaccine

Not for the plague.

The plague came back several times, but then really died out I think by the 18th C. There are actually a few cases of it in every year, but most come from being bitten by something infected (fleas are the scary ones). And now it can be treated with antibiotics.
Yay for medical progress-- don't even need a vaccine for this one.

Of course, now we have Lyme and West Nile for the insect-borne diseases.

[Ocelot II]

23. Also, the plague isn't caused by a virus but by a bacterium, Yrsinia pestis,

which is why these days it can be treated with antibiotics.

[viva la]

24. Interestingly-- Lyme comes from a bacterium

But West Nile is a virus-- both insect-borne.

The perfect little vehicles.

[ismnotwasm]

13. Yes.

[brewens]

14. I heard right from the start that was definitely worth hoping for. I bet Fauci didn't want to

say a whole lot about that. TFG may have heard that though and ran with it. I the luckiest case scenario, maybe that could have happened, and it really would have dwindled to nothing when it got warm outside. I don't need Spock to tell me those odds were long.

[barbtries]

15. the answer is yes.

all a virus wants is to reproduce, so it is very possible that it would mutate to be less virulent in order to continue reproducing. A doctor I work with just pointed that out to me a couple days ago.

[Swede]

16. I've read that there are thousands of variatons of the covid virus, most are harmless.

Every now and then one mutates that is harmful. It eventually mutates again into the harmless kind.

[enki23]

17. That's not quite right, no.

Most of the variants, and most amino acid changes, won't provide a selective advantage. That doesn't have to make them "harmless." It's highly unlikely for any successful variant of this virus to be harmless. At base, it just means most variants aren't going to be more harmful. Natural selection will work to balance the needs of the virus to reproduce in human cells with the need of the virus to have a longer window in which to transmit. There isn't necessarily a single optimum, and evolution doesn't function to find the optimum anyway. It finds strategies that work, optimized or not.

Natural selection isn't particularly smart. It doesn't plan things. As far as we know, it's just as likely to become a *nastier* disease, which gives it a shorter window but a greater production, as it is to do the reverse. And to further complicate things, optimal transmission behavior for this virus is going to also be dependent on *our behavior toward it.* Natural selection works toward successful reproduction within a particular environment. In this case, humans are the environment. With all that entails.

https://en.wikipedia.org/wiki/Optimal_virulence

[Earth-shine]

19. The virons are very fragile. It doesn't take much to break those protein chains.

It's an amazing feat of statistics that a new viable variant can be created by sheer force of reproductive numbers.

Most changes to the virus would conceivably weaken it, but it's the viable ones that would keep reproducing.

[ProfessorGAC]

21. On Top Of That...

...oxidation or hydrolysis of the proteins themselves requires fairly benign reaction conditions.
Oxidize one double bond, or hydrolyze off one terminal nitrogen and it's not a protein anymore.
That eliminates reproduction.
So, everything is fairly "fragile" which is why everybody getting vaxxed would have been so powerful.

[Whatthe_Firetruck]

20. Survival of the deadliest...

Milder variants are more likely to be wiped out by our counter measures. It's the really virulent ones that will have more of a chance to continue and mutate, gaining chances to to get even worse.

[Earth-shine]

22. There is a distinction between how deadly a virus is and how successful it is at reproduction. nt