The Covid-19 vaccination rollout in the United States has been much slower than anticipated, with fewer than 7 million people having received a shot by Jan. 7, 2021, far short of the goal of 20 million by the end of December 2020.
However, new attempts are being made in streamlining the vaccination process. This may speed up the rate that shots are delivered, or it may do very little. So:
When will 50% of the US population be vaccinated against Covid-19?
Resolves positive when 165 million people in the US have completed their course of vaccination (so, after both shots for multi-shot treatments) for a vaccine with efficacy >70%. Resolution via credible media reports.