Pre-orders of Covid-19 vaccines top five billion

Although none of the coronavirus vaccines under development has proved its efficacy yet in clinical trials, at least 5.7 billion doses have been pre-ordered around the world. First shipments of a Covid-19 vaccine created by Western laboratories have often been snapped up by the United States. Five vaccines - three Western and two Chinese - are in Phase 3 efficacy trials involving thousands of people. In a surprise announcement, Russian President Vladimir Putin claimed today that a vaccine dubbed 'Sputnik V' - after the Soviet satellite - conferred "sustainable immunity" against the coronavirus. As research laboratories around the...