Influenza reproduces differently from SARS-CoV-2. I think the term is "recombinant virus" [0], making it mutate much more, it's like a regularly shape-shifting virus.

From what I've read about SARS-CoV-2 it doesn't reproduce that way, it mutates relatively slowly in the usual random minor errors fashion.

Because of the slow mutation rate of SARS-CoV-2, we're able to easily trace its spread across the globe by comparing genomes of collected samples. [1]

This of course also bodes well for vaccination efforts, as well as developing robust herd immunity.

[0] https://en.wikipedia.org/wiki/Recombinant_virus#Natural_reco...

[1] https://www.nationalgeographic.com/science/2020/03/how-coron...

We always get immunity to each flu, or we'd all be dead.

So we will get herd immunity to COVID-19, or all be dead. And that hasn't happened in the last million years.

There is no vaccine yet, so the only sure thing is herd immunity. The US is especially vulnerable because we have so many patients in so many locations - testing and tracing isn't going to work in the US. The horse left the barn on that one.

And herd immunity is not going to work very well with a virus if it's been engineered to overcome that.

"The SARS-CoV-2 spike is significantly different from any other Sars that we have studied"

https://www.cambridge.org/core/services/aop-cambridge-core/c...

Yes, we do have herd immunity to the common flu. It's why, for most people with healthy immune systems, the flu is a real annoyance, but nothing more. For those with compromised immune systems, such as AIDs patients, the old, and the very young, the flu can be a disaster. But, once a young child gets the flu a few times, they develop herd immunity so that subsequent infections are less severe.

Once in a while a flu virus learns to trigger the immune system of those with immunity to flu viruses, and then flu pandemics happen, but that is a rare occurence relatively speaking.

> But, once a young child gets the flu a few times, they develop herd immunity

herd immunity is a property of the herd and not any single person, though.

yea, the fact that most children get the flu is a counter example to herd immunity. Full scale herd immunity would protect vulnerable members of societies (who don't have immunity) of contracting the disease in the first place.

You could be immune but be a carrier?