No, it isn't. That is one of the many things that is very, very UNCLEAR.It's an admission that efficacy wanes, but saying their "worthless" is ridiculous. Vaccines work a LOT better than nothing. That much is 100% clear.
Boy, the medical industry sure screwed this up big time. I suppose the basic problem is that they weren't given the usual 20 years to develop a vaccine. Not that they always can even so: HIV still doesn't have anything at all after 40 years, and it's an mRNA virus like Covid. Looking back, that fact was a bad sign.
Hubris. They didn't know what they couldn't do. They thought they were Magic Men, could do Anything and be Superheroes.
Not so much.