The fact that the virus would change was obvious from the start. Coronaviruses always do mutate fast, it's why nobody bothered making vaccines for then before. The narrative changed not because the emergence of yet another variant was unexpected but because the narrative was always and everywhere whatever would convince people to take shots, not what was true.
For what it's worth, we knew really early that the vaccine reduced severe illness primarily. People continued to be, and still are, inaccurate.
The trials didn't even measure "severe illness", so no, we definitely didn't know that by any definition of early. Actually that claim only came to the fore as effectiveness against infection collapsed and a new justification was required.
> “So even though there are breakthrough infections with vaccinated people, almost always the people are asymptomatic and the level of virus is so low it makes it extremely unlikely — not impossible but very, very low likelihood — that they’re going to transmit it,” Fauci said.
So, very few get it at all, and the ones who get it, can't spread it, even without masks. This (well, similar, from our local agencies) was the info I got when i went to get vaccinated.
You can still get it.
You are agreeing with me.
If you want people to trust you, you have to be honest. If you make obvious lies then you get caught and trust is destroyed. The CDC repeatedly lied and misled the American public and now is having trust issues leading to people not getting vaccinated like they should.
If you want to be trusted, don't lie.
The vaccine was never going to be great against variants (though some people did claim it would be just as good with little evidence) and the more removed the variants get (ie, variant of a variant) the less chance those older vaccines have of resisting them.
So it's not exactly that the "narrative changed" so much as that the virus changed and the narrative didn't keep up fast enough.