[dbsights]

Covid-19 is actually a great example. The spike protein was highly conserved until it became advantageous for it mutate to evade the highly-specific immunity created by mRNA vaccines. Then we got Omicron.

[bsder]

For which the original vaccines are still reasonably effective at keeping you out of the hospital (systemic immunity response).

I am awaiting the trials on the ones that actually provoke immunity in the respiratory mucosa. It would be very nice to not get Covid at all.