Inside the dome of a Belgrade concrete fair hall, dozens of nurses in hazmat suits vaccinate young and old alike, working with an efficiency that has turned Serbia into continental Europe's fastest vaccinator. The small Balkan country has inoculated more than 450,000 of its seven million population against Covid-19 in almost two weeks, a rate that exceeds all other states in Europe apart from the United Kingdom, according to the scientific publication Our World in Data. One key difference is that most of the vials are filled with a vaccine made by Chinese pharmaceutical giant Sinopharm.