The Netherlands has banned passenger flights from the U.K. in response to reports of a new strain of SARS-CoV-2 that spreads more easily. Planes can bring passengers to the U.K. but must return without passengers. The virus mutation has been detected in Denmark and Australia, but has not been discovered in the U.S. (yet).
What we know so far is that U.K. scientists believe it is far more transmissible, but doesn’t seem to be more dangerous, and shouldn’t mitigate the effectiveness of vaccines.