Social distancing remains key during vaccinations.

A global effort to develop vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began early in 2020. In mid-December, the U.S. Food and Drug Administration approved emergency use authorization for two vaccines that successfully concluded their phase 3 trials ([ 1 ][1]), and vaccine distribution in the United States began shortly afterwards. As vaccinations progress, the public must continue to social distance, limit large gatherings, wear masks, and engage in other non-pharmaceutical interventions (NPIs) to curb the spread of COVID-19. Both the Pfizer/BioNTech and Moderna vaccines use mRNA technology and require two doses administered 3 and 4 weeks apart, respectively, to reach the full 90 to 95% efficacy ([ 2 ][2]). In light of limited supply, the Centers for Disease Control and Prevention has provided preliminary guidance indicating that vaccination should be prioritized first for health care workers and long-term care facility residents, then for other essential workers, and next for people at higher risk for severe illness ([ 3 ][3]). Subsequently, vaccination will reach most sectors of the population, though inoculation of children under 16 has yet to be recommended. Globally, vaccination uptake over the coming year could prevent disease for the sizeable portion of the population that has yet to be infected with SARS-CoV-2 and move the world to a post-pandemic phase; however, this potential benefit of averted infections, hospitalizations, and deaths depends considerably on societal maintenance of NPIs during vaccine deployment. Relaxing NPIs before attaining adequate distribution would enable infection of many more people before their vaccination than would occur if NPIs were to be maintained or increased. Locally, relaxation of NPIs increases the reproduction number, Rt , which enables greater transmission of the virus and a larger overall attack rate. These changes lead to a faster and larger accumulation of infections that could greatly outpace vaccination distribution efforts. Thus, maintaining NPIs throughout the upcoming SARS-CoV-2 vaccination campaign is essential for maximizing the health benefit. In the coming months, public health messaging is critically needed to encourage continued compliance with NPI control measures. 1. [↵][4]U.S. Food and Drug Administration, “COVID-19 vaccines” (2020); [www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/covid-19-vaccines][5]. 2. [↵][6]1. C. Zimmer, 2. J. Corum, 3. S.-L. Wee , “Coronavirus vaccine tracker,” The New York Times (2020). 3. [↵][7]Centers for Disease Control and Prevention, “How CDC is making COVID-19 vaccine recommendations” (2020); [www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations-process.html][8]. Pfizer Inc. reviewed this manuscript and approved the decision to submit the manuscript for publication. F.J.A., A.C., and D.L.S. own Pfizer stock. J.S. and Columbia University disclose partial ownership of SK Analytics. J.S. has done paid consulting work for Business Network International and receives funding from Pfizer Inc., National Science Foundation grant DMS-2027369, and a gift from the Morris-Singer Foundation. [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #xref-ref-1-1 "View reference 1 in text" [5]: http://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/covid-19-vaccines [6]: #xref-ref-2-1 "View reference 2 in text" [7]: #xref-ref-3-1 "View reference 3 in text" [8]: http://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations-process.html