Modeling COVID-19 scenarios for the United States
Authors:   IHME COVID-19 Forecasting Team, Reiner Robert C. , Barber Ryan M. , Collins James K. , Zheng Peng , Adolph Christopher , Albright James , Antony Catherine M. , Aravkin Aleksandr Y. , Bachmeier Steven D. , Bang-Jensen Bree , Bannick Marlena S. , Bloom Sabina , Carter Austin , Castro Emma , Causey Kate , Chakrabarti Suman , Charlson Fiona J. , Cogen Rebecca M. , Combs Emily , Dai Xiaochen , Dangel William James , Earl Lucas , Ewald Samuel B. , Ezalarab Maha , Ferrari Alize J. , Flaxman Abraham , Frostad Joseph Jon , Fullman Nancy , Gakidou Emmanuela , Gallagher John , Glenn Scott D. , Goosmann Erik A. , He Jiawei , Henry Nathaniel J. , Hulland Erin N. , Hurst Benjamin , Johanns Casey , Kendrick Parkes J. , Khemani Apurva , Larson Samantha Leigh , Lazzar-Atwood Alice , LeGrand Kate E. , Lescinsky Haley , Lindstrom Akiaja , Linebarger Emily , Lozano Rafael , Ma Rui , Månsson Johan , Magistro Beatrice , Herrera Ana M. Mantilla , Marczak Laurie B. , Miller-Petrie Molly K. , Mokdad Ali H. , Morgan Julia Deryn , Naik Paulami , Odell Christopher M. , O’Halloran James K. , Osgood-Zimmerman Aaron E. , Ostroff Samuel M. , Pasovic Maja , Penberthy Louise , Phipps Geoffrey , Pigott David M. , Pollock Ian , Ramshaw Rebecca E. , Redford Sofia Boston , Reinke Grace , Rolfe Sam , Santomauro Damian Francesco , Shackleton John R. , Shaw David H. , Sheena Brittney S. , Sholokhov Aleksei , Sorensen Reed J. D. , Sparks Gianna , Spurlock Emma Elizabeth , Subart Michelle L. , Syailendrawati Ruri , Torre Anna E. , Troeger Christopher E. , Vos Theo , Watson Alexandrea , Watson Stefanie , Wiens Kirsten E. , Woyczynski Lauren , Xu Liming , Zhang Jize , Hay Simon I. , Lim Stephen S. , Murray Christopher J. L. 
Published: October 2020

We use COVID-19 case and mortality data from 1 February 2020 to 21 September 2020 and a deterministic SEIR (susceptible, exposed, infectious and recovered) compartmental framework to model possible trajectories of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and the effects of non-pharmaceutical interventions in the United States at the state level from 22 September 2020 through 28 February 2021. Using this SEIR model, and projections of critical driving covariates (pneumonia seasonality, mobility, testing rates and mask use per capita), we assessed scenarios of social distancing mandates and levels of mask use. Projections of current non-pharmaceutical intervention strategies by state—with social distancing mandates reinstated when a threshold of 8 deaths per million population is exceeded (reference scenario)—suggest that, cumulatively, 511,373 (469,578–578,347) lives could be lost to COVID-19 across the United States by 28 February 2021. We find that achieving universal mask use (95% mask use in public) could be sufficient to ameliorate the worst effects of epidemic resurgences in many states. Universal mask use could save an additional 129,574 (85,284–170,867) lives from September 22, 2020 through the end of February 2021, or an additional 95,814 (60,731–133,077) lives assuming a lesser adoption of mask wearing (85%), when compared to the reference scenario.