Johnson & Johnson's Covid-19 vaccine facing struggles in Europe

At the height of Europe's vaccine supply crisis in March, Johnson & Johnson's (J&J) single-dose COVID-19 vaccine was touted as a game-changer. But two months into its rollout, the shot has the lowest uptake of all four approved vaccines. Supply problems, safety concerns, improved deliveries of rival vaccines and countries' inoculation strategies have all played a part in