All I want for Christmas is EU
That is a real possibility. Yes. Still. A vaccine that worked only for a year or even a few months would be better than a kick in the teeth. It is very possible we are going to end up having to take Covid vaccines on a fairly regular basis. That wouldn't be ideal. But it would be better than the alternative of not finding any sort of vaccine by a long way.There's no guarantee.
What if the virus is different every year like the seasonal flu. You'd need a new vaccine every year. Or perhaps the immunity of a vaccine will only be temporary, for weeks or months only.
We haven't got rid of many viruses in the last decades since no vaccine were ever found, only treatments work for those.
It's possible that Covid19 will affect humanity for a long time. We missed our chance to get a head start with Sars-Cov (2002) and with Mers-Cov (2012) to work on finding a cure or vaccine for those coronaviruses. Instead of that there were cuts in the medical research worldwide. Those viruses were seen as not dangerous enough to be worth the investments. That was dumb because the warnings have been there for a while that a pandemic was coming eventually.
We're lucky that it is not so deadly, but the sad thing is that the collateral victims could be many millions of deaths from famines or other issues resulting from the chaos of the pandemic.