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Comment by smorgusofborg | Hacker News Reader

> what's the point, if natural infections are the only way to get protective immunity?

Natural infection from back with the original virus? I've not seen any evidence and can't think of a logical reason why it would be more effective than a vaccine based on the original virus.

I think the real problem is going to be people who were never exposed to the virus getting a variant that is transmitting effectively through people with immunity to the original virus from any source. A way for a variant to get to that is to reach levels that kill anyone not previously exposed. Fear for people who have an immunity I find misplaced, for those who are immunized or survive an ever more dangerous first infection this is going to be our new flu, and it will send people to hospital and very rarely kill.

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> can't think of a logical reason why it would be more effective than a vaccine based on the original virus.

Because the body's immune system can target the entire virus, and not just the spike protein.

But is there any evidence that this matters or has a noticeable impact?

I also imagine that the vaccine simulates a much higher viral load than a mild case.

> But is there any evidence that this matters or has a noticeable impact?

I came across this paper [0] that seemed to be saying their tests showed that the vaccine antibodies better handled the receptor mutations they created (how much better? 100%? or 1%?), but that antibodies from a natural infection target other parts of the virus besides just the receptor (possibly offering broader protection):

> Therefore, antibody immunity acquired by natural infection or different modes of vaccination may have a differing susceptibility to erosion by SARS-CoV-2 evolution.

> The neutralizing activity of vaccine-elicited antibodies was more targeted to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein compared to antibodies elicited by natural infection. However, within the RBD, binding of vaccine-elicited antibodies was more broadly distributed across epitopes compared to infection-elicited antibodies.

There's so much they don't know about the immune system. The above doesn't even get into T-cells.

> I also imagine that the vaccine simulates a much higher viral load than a mild case.

I found the article on these Massachusetts cases interesting. They found a bunch of vaccine breakthrough cases, not cases amongst people who already had covid. On it's own that seems to imply natural immunity might be better, don't you think? Have you seen anything to the contrary?

Maybe too close to call at this point. Could go either way.

[0] https://pubmed.ncbi.nlm.nih.gov/34103407/

Even with the vaccines there are many antibodies for other parts of the virus than have mutated , they're just not very effective.

There are also inactivated whole virus vaccines, they're not very effective either.

Going to preface with I think the vaccines are useful and important, and we should all be vaccinated with the current vaccines.

That said, current vaccines don't provoke the exact same response as an actual infection, particularly in that they don't fully stimulate an immune response in the mucous membranes of the upper repository tract. Here's an Scientific American round-up article (from back in March): https://www.scientificamerican.com/article/to-beat-covid-we-...

Wouldn't "fully stimulat[ing] an immune response in the mucous membranes of the upper respiratory tract" be indistinguishable from having a bad cold?

More or less. The current vaccines are excellent at helping the body stop the virus as it progresses into the lungs and further (thus the massive reduction in severe illness and deaths). But it still means that there's a period of a few days after initial infection when a vaccinated person has a relatively naive immune response (while the virus is mostly just in the nose/throat). This would then result in the person still being pretty contagious.

Do you know if there's a possibility of a nasally administered vaccine, if that'd have some of the desired effect? I know in animals some vaccines are...I don't even know, inhaled liquid I think it is. Doesn't seem that pleasant, but if it reduces contagion maybe it's worth it.

https://www.jenner.ac.uk/volunteer/recruiting-trials/covid-1...

You must not:

Have previously received an adenovitus vectored vaccine

Have previously been vaccinated against COVID-19

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