Projected resurgence of COVID-19 in the United States in July—December 2021 resulting from the increased transmissibility of the Delta variant and faltering vaccination
Creators: name: Machi, Dustin
name: Vespignani, Alessandro
name: Dent, Juan
name: Kaminsky, Joshua
name: Karlen, Dean
name: Healy, Jessica M
name: Viboud, Cecile
name: Chen, Jiangzhuo
name: Bhattacharya, Parantapa
name: Thill, Jean-Claude
name: Marathe, Madhav
name: Mu, Kunpeng
name: Lee, Elizabeth C
name: Yamana, Teresa K
name: Biggerstaff, Matthew
name: Wilson, Shelby
name: Chen, Shi
name: Lewis, Bryan
name: Hill, Alison
name: Adiga, Aniruddha
name: Kinsey, Matt
name: Shaman, Jeffrey L
name: Contamin, Lucie
name: Qin, Michelle
name: Davis, Jessica T
name: Truelove, Shaun
name: Smith, Claire P
name: Porebski, Przemyslaw
name: Srivastava, Ajitesh
name: Lessler, Justin
name: Shea, Katriona
name: Slayton, Rachel B
name: Xiong, Xinyue
name: Lemairtre, Joseph C
name: Pei, Sen
name: Outten, Joseph
name: Johansson, Michael A
name: Vullikanti, Anil
name: Paul, Rajib
name: Howerton, Emily
name: Galanti, Marta
name: Mullany, Luke C
name: Shin, Lauren
name: Rainwater-Lovett, Kaitlin
name: Tallaksen, Kate
name: Harrison, Galen
name: Pastore y Piontti, Ana
name: Venkatramanan, Srinivasan
name: Chinazzi, Matteo
name: Levander, John
name: Kerr, Jessica
name: Hochheiser, Harry
name: Runge, Michael C
name: Klahn, Brian
name: Hoops, Stefan
name: Janies, Daniel
name: Perez-Saez, Javier
name: Borchering, Rebecca K
name: Hurt, Benjamin
name: Orr, Mark
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2022

description: In Spring 2021, the highly transmissible SARS-CoV-2 Delta variant began to cause increases in cases, hospitalizations, and deaths in parts of the United States. At the time, with slowed vaccination uptake, this novel variant was expected to increase the risk of pandemic resurgence in the US in summer and fall 2021. As part of the COVID-19 Scenario Modeling Hub, an ensemble of nine mechanistic models produced 6-month scenario projections for July–December 2021 for the United States. These projections estimated substantial resurgences of COVID-19 across the US resulting from the more transmissible Delta variant, projected to occur across most of the US, coinciding with school and business reopening. The scenarios revealed that reaching higher vaccine coverage in July–December 2021 reduced the size and duration of the projected resurgence substantially, with the expected impacts was largely concentrated in a subset of states with lower vaccination coverage. Despite accurate projection of COVID-19 surges occurring and timing, the magnitude was substantially underestimated 2021 by the models compared with the of the reported cases, hospitalizations, and deaths occurring during July–December, highlighting the continued challenges to predict the evolving COVID-19 pandemic. Vaccination uptake remains critical to limiting transmission and disease, particularly in states with lower vaccination coverage. Higher vaccination goals at the onset of the surge of the new variant were estimated to avert over 1.5 million cases and 21,000 deaths, although may have had even greater impacts, considering the underestimated resurgence magnitude from the model.