Trends in Laboratory-Confirmed SARS-CoV-2 Reinfections and Associated Hospitalizations and Deaths Among Adults Aged ≥18 Years — 18 U.S. Jurisdictions, September 2021–December 2022
C. Kevin, Vajeera Dorabawila, Tomás M. León, Hannah Henry, Amelia G. Johnson, Eli S. Rosenberg, Joshua Mansfield, Claire M. Midgley, Ian D. Plumb, Julia Aiken, Quratul Ain Khanani, Steven Auche, Nagla S. Bayoumi, Sarah A. Bennett, Carmen Bernu, Carolyn Chang, Kathryn Como‐Sabetti, Kevin Cueto, Spencer Cunningham, Meredith Eddy, Rebecca Falender, Aaron T. Fleischauer, Darren M. Frank, Pauline Harrington, Mikhail Hoskins, Adam Howsare, Lucy M. Ingaiza, A.S.M.D. Ashraful Islam, Shelli A. Jensen, Jefferson M. Jones, Grace Kambach, FNU Kanishka, Yuriy Levin, John Masarik, Stéphanie Meyer, Lauren Milroy, Keeley J. Morris, John Olmstead, Nina S. Olsen, Enaholo Omoike, Komal Patel, Amanda Pettinger, Melissa Pike, Isaiah G. Reed, Elizabeth Slocum, Melissa Sutton, Buddhi Tilakaratne, Hailey Vest, Johanna Vostok, Jennifer S. Wang, Lydia Watson-Lewis, Haley Wienkes, Melissa Briggs Hagen, Benjamin J. Silk, Heather M. Scobie
Abstract
Although reinfections with SARS-CoV-2 have occurred in the United States with increasing frequency, U.S. epidemiologic trends in reinfections and associated severe outcomes have not been characterized. Weekly counts of SARS-CoV-2 reinfections, total infections, and associated hospitalizations and deaths reported by 18 U.S. jurisdictions during September 5, 2021-December 31, 2022, were analyzed overall, by age group, and by five periods of SARS-CoV-2 variant predominance (Delta and Omicron [BA.1, BA.2, BA.4/BA.5, and BQ.1/BQ.1.1]). Among reported reinfections, weekly trends in the median intervals between infections and frequencies of predominant variants during previous infections were calculated. As a percentage of all infections, reinfections increased substantially from the Delta (2.7%) to the Omicron BQ.1/BQ.1.1 (28.8%) periods; during the same periods, increases in the percentages of reinfections among COVID-19-associated hospitalizations (from 1.9% [Delta] to 17.0% [Omicron BQ.1/BQ.1.1]) and deaths (from 1.2% [Delta] to 12.3% [Omicron BQ.1/BQ.1.1]) were also substantial. Percentages of all COVID-19 cases, hospitalizations, and deaths that were reinfections were consistently higher across variant periods among adults aged 18-49 years compared with those among adults aged ≥50 years. The median interval between infections ranged from 269 to 411 days by week, with a steep decline at the start of the BA.4/BA.5 period, when >50% of reinfections occurred among persons previously infected during the Alpha variant period or later. To prevent severe COVID-19 outcomes, including those following reinfection, CDC recommends staying up to date with COVID-19 vaccination and receiving timely antiviral treatments, when eligible.