COVID-19 seasonality in temperate countries.

Area of Science:

• Epidemiology
• Environmental Health
• Public Health

Background:

• The impact of vaccination, social distancing, and restrictive measures on SARS-CoV-2 mortality is established.
• The role of seasonality in SARS-CoV-2 transmission and mortality remains poorly understood and underutilized in public health strategies.

Purpose of the Study:

• To investigate the seasonality of SARS-CoV-2 in temperate climate countries.
• To analyze the association between temperature, vaccination rates, and COVID-19 mortality.

Main Methods:

• Data on mortality, vaccination rates, and temperature were collected for temperate climate countries.
• Stringency index for government response trackers was used to quantify restriction policies.
• Statistical analyses, including correlation and multivariate regression, were employed to assess relationships.

Main Results:

• A significant negative correlation was observed between monthly temperatures and COVID-19 mortality rates across temperate regions.
• Multivariate regression models confirmed that higher temperatures were associated with lower mortality.
• The effectiveness of vaccination campaigns on reducing mortality was found to be greater during colder periods.

Conclusions:

• SARS-CoV-2 exhibits seasonal patterns, with decreased mortality during warmer months in temperate zones.
• Public health strategies for managing COVID-19 and future pandemics should incorporate seasonal considerations.
• Accounting for seasonality can help minimize mortality, reduce healthcare system burden, and sustain economic and social activities.