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Comment by bart__ | Hacker News Reader

It is possible the spike proteins mutate too much and we need a booster

This should be relatively easy to verify, we have millions of people who have been infected early last year so we can see how many of them got reinfected recently with one of the more recent strains.

If the immune response of the virus is close enough to what a vaccine gives and the mutation rate remains relatively constant, the number of reinfections would probably be a good indication of how much would we need subsequent shots, at least for a yearly renewal cycle.

I wonder, are there any such studies?

Is that still a booster at that point?

That'd be no (for natural immunity). Even SARS-1 survivors have immunity to COVID, all these years later.

Maybe for the synthetic immunity (who knows).

But in any case, SARS-1 and covid are about 80% similar. The "variants" of different covids are about 99.7% similar. Draw your own conclusions.

I did not know that, honestly quite surprised! One thing to keep in consideration is that there is a very big evolutionary pressure for covid to get a mutation that bypasses the vaccine antibodies and still infect others, given that there are so many active infections still out there. I now have good hope though!

You didn't know that, because it's most likely BS.

BTW people and chimpanzees share 99% of their DNA. We're basically the same, aren't we. /s

80% is not close at all, and 99.7% still can render a vaccine ineffective, of course the specifics matter.

To be fair humans are almost identical to chimpanzees biologically in many ways. As long as the spike proteins tertiary structure has not changed to much from SARS to COVID, op could be correct. Emphasis on could.

Emphasis affirmed.

I feel like talking about genes in % similarity seems to be useless.

That was the point I was trying to drive home, more or less.

Do you have a source for your claim? Can't find anything about SARS, covid transimmunity.

Here's something [0]:

> Next, we showed that patients (n = 23) who recovered from SARS (the disease associated with SARS-CoV infection) possess long-lasting memory T cells that are reactive to the N protein of SARS-CoV 17 years after the outbreak of SARS in 2003; these T cells displayed robust cross-reactivity to the N protein of SARS-CoV-2.

[0] https://pubmed.ncbi.nlm.nih.gov/32668444/

Thank you, seems to support OP's statement. Given that COVID antibody tests also show cross-reactivity with SARS it seems likely to me he is in fact correct.

Seconding the request for a source. The papers I've found say that SARS-1 survivors have antibodies that react to SARS-CoV-2 but don't neutralize the virus, and thus may not provide immunity.

So far the mRNA vaccines have shown strong effectiveness against the variants, but the others like AZ and the Chinese/Russian vaccines much less so. It's also worth noting that natural immunity is a somewhat random process (more random than the antibodies produced with vaccines) and not everyone develops the same level of protection.

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