A light at the end of the tunnel?

Good evening

So should we be starting to get excited that a Covid vaccine is just around the corner?
The news that one of the vaccines currently in trial has posted a 90 per cent success rate would on the face of it seem to be the best pre-christmas present any of us could hope for.
Around 44,000 people took part in the trial and 94 people contracted Covid, but critically 86 of them had been given a placebo - not the real vaccine - and so had no immunity anyway.
So this certainly sounds like the scientists are on the right track.
However, there is still plenty of work to do. For example, how long will the vaccine last? A lifetime? A year? Just a few months?
And of course, we can never be sure that the virus will not mutate, rendering any initial vaccine obsolete quickly.
But let’s be positive for now. There is at least the potential of some light at the end of the tunnel and it could even be life-changing.
And given that we are currently going through our second lockdown in less than a year, that’s a straw we should grasp very tightly indeed.