The starting gun was sounded as far back as the weekend of January 11-12, when Chinese authorities released the full sequence of the COVID-19 genome. The ‘vaccine race’ has now grown to field some 118 potential candidates and seen unprecedentedly short projected completion windows—most experts endorse a 12-18 month ‘best-case scenario’. Traditionally, a vaccine’s clinic-to-market cycle can take upwards of a decade. Though the global health emergency brought on by COVID-19 has looked like catalysing that marathon into a sprint, the race has regulatory, scientific and market hurdles to overcome: the transitionfrom proof-of-principle to commercial development will be plagued by bottlenecks. And attrition too will play its part: industry benchmarks peg the failure rate at greater than 90 per cent. No wonder the European Medicines Agency dismisses claims of a ‘cure by Christmas’.