Comment by cartoonworld | Hacker News Reader

Comment by cartoonworld | Hacker News Reader

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Unfortunately, every time Sars-CoV-2 spreads and increases its infection tally, mutation can occur which has a chance to beneficially influence selection in the next infection cycle.

Unlike how bacterial infections could gain or incrementally increase some of its antibiotic immunity or other attributes thanks to the conditions in a single host, for example incomplete or unnecessary antibiotic regimens, viral infections need to be infecting new cells in order to experience meaningful mutations. This is where immune function influences viral mutation.

Less immunity will result in more cell infection which directly creates opportunities for mutations as the virus replicates. If a vaccine improves host immunity enough that they replicate less virus, they will cause much less mutation. The relationship is non-linear because of the multiplicative nature of viral spread (r0?)

My opinion is that isn't anybody's "fault" that a pandemic virus is causing such unbelievable mayhem, but vaccinations and immunology is the truest course to achieving excellent results going forward.

Edit: Virus does not require fresh host to mutate

this isnt the case. The virus spreads within your body and the mutations will spread within the body as well. A virus can mutate and improve within the host.

What doesnt necessarily get selected for within the host is improved survival rates outside the body, ability to penetrate the body in the first place, etc. But bacteria are under the same evolutionary pressures.

>The virus spreads within your body and the mutations will spread within the body as well. A virus can mutate and improve within the host.

Agreed.

There is a bucket of vulnerable ACE-2 receptors in everybody. Once a viral infection occurs in a single person, it undergoes an infection curve within the host bucket, analogous to the infection curve of the general population. The non-linear host cell infection curve can be greatly influenced by early intervention (immunity). It can be expected that some people have a big curve that results in a more complete viral infection than in others, but the number is limited until it can move to a new person, and run a new infection curve. So the mutation can occur in that once person, but it has to replicate in a new host to see the new infection curve of the viral prototype. If one never transmits the prototype, it is moot.

Bacterial resistances like MRSA are most likely when an infection that is able to survive treatment is able to re-establish. With most susceptible bacterial cells having now been eliminated in this case, the new infection is more formidable. There are of course other mutation vectors.

> viral infections need to be infecting new hosts in order to experience meaningful mutations.

Interesting! What causes this, is there some keyword i can search for in order to learn more?

The assertion is not correct, viruses do not need to spread to new hosts to experience meaningful mutation.

Yes, it is much more precise to state that they must be replicating in order to mutate. I've edited my comment to reflect this, Thanks :)

If RNA is damaged and changed and the virus particle is destroyed or for some reason never replicates, I don't count that as mutating, but then again what do I know.

bacteria mostly need to be replicating to spread mutations as well.

There are mechanisms for bacteria to uptake dna in the environment and incorporate it (e.g. antibiotic resistance). But without replication of the bacteria the resistance wont spread.

One interesting point is that in general biology they teach that lamarckian evolution doesnt exist, but bacterial uptake of DNA demonstrates that it does exist.

Yes but the bacterial infection can go up and down or last a while, this is a general case for bacteria.

The Sars-CoV-2 virus (provisionally) doesn't seem to infect and then suppress only to re-emerge later in a new infection, or hang around as an active infection for months. People get sick and their illness lasts a big armful of days.

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