From the conclusion of a new paper by my AEI colleagues Kieran Allsop, James Capretta, and Scott Ganz:
The arrival of effective vaccines has raised hopes that the US can move past the worst of the COVID-19 pandemic in the coming months. This optimistic outlook rests on the assumption that the vaccines will remain effective, even as the virus mutates, and that the process of producing and administering the vaccines will continue to improve in the coming weeks.
If those assumptions hold, then, using reasonable assumptions, 50 percent of the country could be protected from COVID-19 by mid-May and 75 percent by mid-June. This projection assumes there will be sufficient demand for vaccinations to reach these thresholds.
(Emphasis mine.)
According to the authors’ analysis, a lot is riding on the Johnson & Johnson vaccine:
However, if the rollout of the Johnson & Johnson vaccine is delayed or not as smooth as hoped, then achieving broad vaccine-induced protection will be a much slower process. The addition of a third candidate will mean that anywhere from 22 to 30 percent more of the population can be vaccinated by July, but reaching this goal will depend entirely on improved vaccination rates.
https://twitter.com/MichaelRStrain/status/1364960763098640384
The authors also emphasize that there can be a lot of improvement even before the U.S. reaches herd immunity:
While herd immunity is likely to require vaccinating at least 75 percent of the population, the societal benefits of lower levels of protection should not be dismissed. Vaccination of even half the country by mid-May would lead to a vast improvement in conditions over 2020 and early 2021, both economically and in terms of morbidity and mortality rates. Thus, no matter where the ceiling on demand ultimately becomes limiting, the goal for now should not change: Whatever can be done to accelerate the pace of vaccine administration should be done. The faster people are vaccinated, the sooner the country can begin to look and operate like it did before the crisis began.
You can read the full paper here.