Meanwhile, rich countries are prospectively buying up vaccines before they have even been cleared for use. The U.S.-Pfizer vaccine deal, and a similar deal with Glaxo PLC and Sanofi AG, uses American buying power to avoid excessive prices. Britain has done four separate deals with providers for 250 million doses.

What about the poorer countries who may have to pay more for the vaccine? For now, attempts at “vaccine justice” have been left to philanthropies such as the Gates Foundation’s Vaccine Network.

How to Ration It?
The pharmaceutical industry cannot produce enough vaccine for the entire global population of almost 8 billion all at once. Therefore, rationing is inevitable. Some people will have to wait. Who gets to make these decisions, and by what criteria?

Within the U.S., various medical bodies and government agencies claim authority to draw up the guidelines. No one seems empowered to adjudicate.

“The principle is to protect those most likely to be harmed,” said Caplan of NYU Langone. That leads to one point of clarity: Medical workers go first. They’re obviously at risk, and have a duty to put themselves in harm’s way.

But after this, following his criterion leads to prioritizing some of the least privileged in society – not because they are underprivileged and deserve help, but because they are most at risk.

Statistically, prisoners follow doctors and nurses on the list of people most likely to be harmed. As prisons are Covid-19 incubators, Caplan suggests that vaccinating inmates would limit the disease’s spread.

Within the U.S., Native-American communities are grievously affected, and therefore have a case for priority. The same is true of some other ethnic minorities, largely because they tend to live in crowded communities, and because higher rates of poverty make them more likely to suffer the underlying conditions that make Covid-19 more deadly.

People are also more at risk if they cannot work from home. In an email, Anthony Skelton, a philosophy professor at the University of Western Ontario and Lisa Forsberg of the Oxford Uehiro Centre for Practical Ethics, make a case for sending those in work-at-home professions to the back of the line.” To the extent that racial minorities might live and/or work in conditions that make them less able to avoid coming into contact with infected individuals, the case for giving them priority over people who can work from their home office seems strong,” the scholars wrote.

All of these proposals spring from prioritizing people according to risk, but might in practice look like the kind of redistributionist social-justice crusading that provokes controversy, particularly in the U.S.