The new variant has mutations to the spike protein that the three leading vaccines are targeting. However, vaccines produce antibodies against many regions in the spike protein, so it’s unlikely that a single change would make the vaccine less effective.
Over time, as more mutations occur, the vaccine may need to be altered. This happens with seasonal flu, which mutates every year, and the vaccine is adjusted accordingly. The SARS-CoV-2 virus doesn’t mutate as quickly as the flu virus, and the vaccines that have so far proved effective in trials are types that can easily be tweaked if necessary.
Peacock said, “With this variant there is no evidence that it will evade the vaccination or a human immune response. But if there is an instance of vaccine failure or reinfection then that case should be treated as high priority for genetic sequencing.”
If it's true that the new strain is 70% more transmissible then that means more people will get sick before we can reach immunity thanks to a vaccine, hospitals will be overwhelmed sooner and more people will die.
So the "problems" it is causing is just that EITHER more stringent restrictions of the same kind are required to contain it OR if uncontained healthcare will be overwhelmed more quickly.
So problems of degree not of kind.