BRUSSELS—More than a quarter of adults in the European Union would be unlikely to take the COVID-19 vaccine when it was offered to them, a survey published on Thursday showed. The results also suggested a strong link between vaccine hesitancy and the use of social media, particularly where social media is the main source of information, according to Eurofound which carried out the survey. “Unfortunately, these findings reflect a failure to deliver persuasive and clear communication regarding the efficacy and safety of vaccines,” said Daphne Ahrendt, Eurofound senior research manager. Bulgarians were the most reluctant to get the vaccine, with 67 percent of adults saying they were unlikely or very unlikely to get it. In Ireland, only 10 percent of adults said they would not get the shot. The survey found an east-west divide across Europe. Except for France and Austria, the intention to get vaccinated was above 60 percent in …