On Dec. 8, 2020, when then-President Elect Joe Biden promised that his incoming administration would deliver 100 million doses of COVID-19 vaccine to patients’ arms in his first 100 days in office, none of the highly anticipated inoculations were yet authorized. Even with highly promising results from medical trials and months of planning by state and federal authorities for the rollout, it is not a safe bet to hinge grand political ambitions on a cat’s cradle of government bureaucracies.

While the U.S. Food and Drug Administration issued an emergency use authorization for the Pfizer-BioNTech vaccine three days later (and another for Moderna’s shot on Dec. 18), the first several weeks of the rollout were ridden with missteps and crossed wires as doses piled up in overstocked long-term care facilities, and in some cases the trash (though there is scant data on the number of wasted treatments). In the 38 days between the first vaccinations on Dec. 14, and when Biden took office on Jan. 20, the federal government had shipped 42 million doses. But less than half—16.5 million shots—were administered. Since then, the pace as picked up considerably, …