A Covid-19 vaccination centre in the Bulgarian capital Sofia is almost empty, a vivid example of the way the country's immunisation effort is hamstrung by what observers say is a mix of various reasons, including fake news and widespread mistrust. As a fourth coronavirus wave threatens the country, official data show that only 15 percent of the country's population of 6.9 million people have been fully vaccinated, far below the EU average of 52.7 percent. IMAGES AND SOUNDBITES