BERLIN—German pharmaceutical company BioNTech is confident that its coronavirus vaccine works against the new UK variant, but further studies are needed to be completely sure, its chief executive said Tuesday. The variant, detected mainly in London and the southeast of England in recent weeks, has sparked concern worldwide because of signs that it may spread more easily. While there is no indication it causes more serious illness, numerous countries in Europe and beyond have restricted travel from the UK as a result. “We don’t know at the moment if our vaccine is also able to provide protection against this new variant,” CEO Ugur Sahin told a news conference the day after the vaccine was approved for use in the European Union. “But scientifically, it is highly likely that the immune response by this vaccine also can deal with the new virus variants.” Sahin said that the proteins on the UK …