Simply waiting for vaccine production to ramp up is inadequate. With thousands of people dying daily, there’s a strong case for stretching the doses we have now. A “first doses first” approach — that is, prioritizing first doses by delaying the second shot from three to four weeks (the period studied in clinical trials) to 12 weeks — would allow more people to get vaccinated quickly, for example. “Fractional” dosing, such as by giving half-doses, would instantly increase the vaccine supply and has been used successfully in previous epidemics. And, of course, we should authorize more vaccines, including Johnson & Johnson’s and AstraZeneca’s (despite one disappointing trial for the latter in South Africa), and the Novavax vaccine. We should take a closer look at Sputnik, the Russian formula, now that it has shown strong results in clinical trials. Finally, to get shots into arms we could ease up on prioritization rules, to streamline the process…

Is it better to give a second dose to one person, boosting them from 80 percent to 95 percent protected, or to give a first dose to someone else, raising them from 0 percent to 80 percent protected? Ethics and efficiency both suggest that it’s better to protect two people well than one person maximally. It’s also a quicker route to herd immunity, a key part of any vaccine strategy.