[SamBam]

> To me this indicates their immune systems are doing a great job and we should rather avoid teaching them (their perfectly competent immune systems) how they should do it.

This makes no sense from an immunological perspective, and sounds like one of those pseudoscientific ideas that "natural" immunity is somehow stronger than "vaccination" immunity.

A vaccine is nothing more than exposing the immune system to the antigens. If their immune systems are already geared up to fight Covid, they will simply respond to the vaccine as another Covid infection and fight it accordingly.

As for whether there is any benefit, there absolutely is. Multiple exposure events greatly increase the storage of the antibodies in the memory cells of the immune system. This is why most vaccines require at least two shots, and why the CDC is now recommending a third booster shot for some people.

Plenty of studies show that the immunity of people who are vaccinated is stronger than those who were infected naturally (e.g. [1]), and that the immunity of people who have had Covid is significantly more robust after subsequent vaccination (e.g. [2], [3]).

1. https://www.biorxiv.org/content/10.1101/2021.04.15.440089v2....

2. https://apnews.com/article/science-health-coronavirus-pandem... ("The survivors who never got vaccinated had a significantly higher risk of reinfection than those who were fully vaccinated, even though most had their first bout of COVID-19 just six to nine months ago.")

3. https://www.medrxiv.org/content/10.1101/2021.04.25.21256049v...

[logicchains]

Yet data from Israel suggests that the vaccinated are six times more likely to get delta than people with natural immunity: https://www.israelnationalnews.com/News/News.aspx/309762.

>This makes no sense from an immunological perspective, and sounds like one of those pseudoscientific ideas that "natural" immunity is somehow stronger than "vaccination" immunity.

There's nothing unscientific about it; it's been known for a while now that some vaccines like the flu vaccine are inferior to natural immunity: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2870374/

[SamBam]

> Yet data from Israel suggests that the vaccinated are six times more likely to get delta

Ok, well I've cited two studies that say the opposite, and one of those studies looked at antibody responses over time from matched individuals. The "on the ground" results in Israel are completely confounded by who is an isn't vaccinated, with at risk people (including healthcare workers) being significantly more likely to be vaccinated.

> it's been known for a while now that ...

Oh my. Did you read that study? It shows nothing of the sort. It is a mathematical Markov simulation of what happens assuming natural infection is stronger than vaccines.

The kicker is in the discussion:

> Under the plausible assumption that protection against influenza infection lasts longer after naturally acquired infection than after vaccination, we show that ...

This is literally begging the question. The authors make the assumption that naturally-acquired immunity is stronger. Then they write a model that repeatedly exposes people given that assumption. Then they "show" that, surprise surprise..... people with naturally-acquired immunity catch the flu less frequently.

[dragonwriter]

> Yet data from Israel suggests that the vaccinated are six times more likely to get delta than people with natural immunity:

In Israel, as almost everywhere else (other than early in the pandemic with nursing homes in many places), implementation of and compliance with vaccination and other COVID countermeasures had been strongest among the elderly and immunocompromised; at the same time, COVID infection has been more likely to lead to death in the elderly. So, the population most likely to be infected if exposed has a higher baseline vaccination rate and a smaller rate of prior COVID infection, both due to countermeasures and inverse survivorship effects. Without controlling for that, which bare population numbers like this don’t do, you have no idea what the relative immunity effect of prior infection vs. vaccination is.