Can SARS-CoV-2 Global Seasonality be Determined After One Year of Pandemic?

The seasonal cycle of respiratory viral diseases is widely recognized.1 A typical seasonal pattern of annual influenza epidemics is observed during the winter season in the northern hemisphere and during the summer season in the southern hemisphere.1,2 This knowledge has suggested that the transmission of SARS-CoV-2 could follow a similar seasonal pattern. Hence, many studies have been conducted to understand the seasonal pattern of COVID-19 since the beginning of the pandemic.3,4 However, a common limitation is the short timeframe since COVID-19 had only been prevalent for less than a year. Consequently, previously reported seasonal patterns could be incomplete and spurious due to the short study period.4Peer reviewe