Seasonal trends in COVID-19 cases, hospitalizations, and mortality in the United States and Europe

• Published in: Scientific reports Vol. 13; no. 1; p. 3886
• Main Authors: Wiemken, Timothy L., Khan, Farid, Puzniak, Laura, Yang, Wan, Simmering, Jacob, Polgreen, Philip, Nguyen, Jennifer L., Jodar, Luis, McLaughlin, John M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08-03-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 692/308/174; 692/700/478/174; Coronaviruses; COVID-19; COVID-19 - epidemiology; COVID-19 vaccines; Europe - epidemiology; Health planning; Hospitalization; Humanities and Social Sciences; Humans; Mortality; multidisciplinary; Public health; SARS-CoV-2; Science; Science (multidisciplinary); Seasonal variations; Seasons; Severe acute respiratory syndrome coronavirus 2; Time series; United States - epidemiology; Vaccines; United States; Europe; United States > US
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-31057-1

Determining whether SARS-CoV-2 exhibits seasonality like other respiratory viruses is critical for public health planning. We evaluated whether COVID-19 rates follow a seasonal pattern using time series models. We used time series decomposition to extract the annual seasonal component of COVID-19 case, hospitalization, and mortality rates from March 2020 through December 2022 for the United States and Europe. Models were adjusted for a country-specific stringency index to account for confounding by various interventions. Despite year-round disease activity, we identified seasonal spikes in COVID-19 from approximately November through April for all outcomes and in all countries. Our results support employing annual preventative measures against SARS-CoV-2, such as administering seasonal booster vaccines in a similar timeframe as those in place for influenza. Whether certain high-risk individuals may need more than one COVID-19 vaccine booster dose each year will depend on factors like vaccine durability against severe illness and levels of year-round disease activity.