World Health Organisation (WHO) director-general Tedros Adhanom Ghebreyesus issued an apposite warning to nations that it would be impossible to rebuild the global economy without vaccinating the planet's highest-risk populations simultaneously. His view was that the fastest way to end the pandemic and reopen economies is to start by protecting the highest-risk populations everywhere, rather than the entire populations of just some countries. Ideally, a vaccine would be available for all at one go. But that would be a logistical impossibility. In the event, the WHO chief has made the important point: That those at highest risk - front-line workers in health and social care settings who come into contact with particularly vulnerable groups and are essential to protecting the population - must be considered to be a single international category.

Nations must abjure the natural temptation to vaccinate all or most of their populations at the expense of those highest-risk groups elsewhere. For example, Australia's deal with British drugmaker AstraZeneca, to produce and distribute enough doses of a potential vaccine for its population of 25 million, is understandable from a national point of view. But it might not advance the country's international economic interests.