There's the Kent variant, the South Africa variant and the Brazilian variant. Where did they come from, and what problems do they cause?
It's evolution in action. The purpose of a virus is to copy itself, and to do so, it uses the mechanisms of our cells. But the copies are not always exact. Sometimes, there is a small mistake in the copy.
This mistake could mean a non-viable virus, and that's a dead end. Or it could mean a virus that is less infectious. Or more infectious.
The more times this copying happens, the more chances there are for a minor copying error. Most such errors don't change infectiousness, but the copying errors that make the virus more infectious will, obviously, spread faster than the original.
So the problem will continue. As the virus gets more and more common, there will be more and more variants which are more infectious. Kent was unfortunate to be hit by one of the first, and now the whole of the UK is suffering.
The vaccine will change the environment. And evolution is about adaptation to the environment.
With that many copies of the virus floating around, it's likely that some of them will be more resistant to the vaccines. And in the same way that bacteria have evolved resistance to antibiotics, so Covid can evolve resistance to the vaccines.
The vaccines will get us off the hook for now. But not for ever. Just as we need a new vaccine for flu each year, we could need a new vaccine for Covid each year.
We have to get ready for that.
I'd suggest three things.
1. We have to stop running the NHS at near 100% capacity. There has to be unued capacity to cope with an epidemic. Yes, that will cost money.
2. We need more doctors and nurses, and we need to get them by paying for their training (bursaries) and paying them well when trained. Yes, that will cost money.
3. We need to have enough medical equipment (for example, PPE) in stock so that if there's another pandemic, we aren't left using bin bags instead. Yes, that will cost money.
This will all cost money, but not as much as it can cost if we don't get ready for the next pandemic.