Also, there is some evidence that the variations that are happening to the virus are converging on the same sorts of mutations in the same places on the genome. This would mean that at some point, they would be able to develop vaccines that are more likely to protect against a number of variants, and thus even boosters wouldn't necessarily be needed forever, even if they are at first while they learn more about the virus and how it changes.
Also, there is work being done to make the vaccine based on a different part of the virus, one that appears to mutate very little. This would require a different method and is apparently more difficult to produce, but if they can successfully do that, then it would be generally resistant to mutations on the spike (which is the area the current vaccines produce antibodies to), and those are the mutations that seem to happen more quickly.
Furthermore, some think that a third dose even of the same vaccine (unaltered for mutations) might still be enough to increase protection so that it is effective against those variants. That might mean that with enough boosters, it doesn't need to be an ongoing thing but that eventually, immunity could build up sufficiently.
Or various other possibilities. None of it is certain yet, so even Matt Hancock is just speculating about things that might happen. I think we'll have to wait and see.
I'd certainly take any and all boosters that are offered, as would all the scientists and medical people I know.