In a recent study posted to the Research Square preprint server*, researchers from Columbia University Mailman School of Public Health, Pfizer Inc, and the University of Iowa assessed the seasonal trends observed in coronavirus disease 2019 (COVID-19) cases, hospitalizations, and deaths.
In the winter, several respiratory viruses cause waves of illness that follow specific seasonal patterns. In addition to increased indoor activity and seasonal weather variations known to affect virus stability outside the host, these trends are likely the result of a confluence of host, pathogen, and environmental factors. Therefore, extensive research is needed to determine whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) currently follows or will eventually follow seasonal patterns similar to these other respiratory viruses.
About the study
In the current study, researchers assessed the seasonal patterns observed in COVID-19 cases, hospitalizations, and deaths in the United States and Europe using temporal models. Read also : Secretary Antony J. Blinken COVID-19 Relief Event – US Department of State.
The ecological survey was carried out by adhering to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) standards. The GitHub repository Our World in Data (OWID) was used to obtain daily rates of COVID-19 infections, hospitalizations, and deaths observed per million of the country‘s population for the United States, the United Kingdom, and all member countries of the European Union. Data used for the study were recorded between March 1, 2020 and July 31, 2022 as available by country.
The team decomposed daily country-specific time series rates corresponding to COVID-19 cases, hospitalizations and deaths individually using a predictive time series model. In addition, the time series model was adjusted for the national severity index.
The study results showed that the model showed clear annual seasonality consistent across all SARS-CoV-2 infections, hospitalizations and death rates recorded between November and April 2021. To see also : DC Health Will Offer At-Home COVID Test Appointments to Residents Needing Reasonable Accommodation | doh. The additional effect of the annual seasonal component on cases was most significant between January and March . 2021, with a peak additional seasonal rate value of 905 cases observed per 1,000,000 people.
Study: Seasonal trends in COVID-19 cases, hospitalizations, and deaths in the United States and Europe. Image credit: fanasiev Andrii /Shutterstock
With up to 100 more seasonal hospitalizations per 1,000,000 noted between November and April, the annual seasonal component for hospitalizations showed a clear distinction between seasons. With an additional two deaths per 1,000,000 people as a result of the annual seasonal effect, which is mainly concentrated from November to February, COVID-19-related mortality showed a similar pattern in the annual seasonal component. All of the countries assessed showed similar patterns. The annual seasonality of pre-pandemic influenza, which was consistently observed between December and April over twelve US influenza seasons, was also demonstrated by the exact model specifications described for rates of COVID-19.
Heat map of the influenza positive rate average annual seasonal component by month, October 2009 to December 2021. Data source: World Health Organization
The study results showed that despite continuous transmission of COVID-19 throughout the year, the number of COVID-19 cases, hospitalizations and deaths was the highest during the winter viral respiratory season in the United States and Europe. See the article : Trust Science… Except for Biology. Therefore, the researchers suggest using annual preventive measures against SARS-CoV-2, such as the administration of seasonal booster vaccines or other non-pharmaceutical interventions to the general public in a time frame similar to those employed for influenza prevention to slow down COVID-19 transmission. .
Research Square publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as decisive, guiding clinical practice/health-related behavior, or treated as established information.