The furor around D.C.’s vaccine prioritization shows how hard it is to get this vaccine to those who need it most.

When Washington, D.C., announced that it would soon prioritize people who are overweight for the Covid-19 vaccine, experts and commentators were perplexed. Nate Silver tweeted that “there’s basically no prioritization at all.” Others questioned the utility of using such a crude measure as body mass index (BMI), with its checkered history, as an indicator of health. Some worried the policy would prioritize overweight young people and smokers over the elderly or those with more pressing conditions like diabetes.

This debate reveals the broader problems facing states and municipalities when it comes to prioritizing the vaccines. The difficulty lies not just in identifying accurate scientific risk factors like medical conditions and underserved demographics, but also in identifying and notifying those most at risk. Read more at The New Republic.