Research led by the Barcelona Institute of Global Health (ISGlobal), published in Nature Computational Science, has provided “robust data” that the disease caused by the SARS-CoV-2 virus results from a “seasonal infection linked to low temperatures”.

This study aimed to answer the question whether SARS-CoV-2 will behave like a seasonal virus like influenza or if, on the contrary, it will be able to propagate at any time of the year.

"The question of whether covid-19 is a genuine seasonal disease is becoming increasingly central, with implications for determining effective intervention measures," said Xavier Rodó, director of ISGlobal's climate and health program and coordinator of the study.

To answer this question, the team of researchers analyzed for the first time the association of temperature and humidity in the early stage of the spread of SARS-CoV-2 in 162 countries, before adopting changes in population behaviour and public health measures. .

According to ISGlobal, the results show a negative relationship between the transmission rate (R0) of the virus and temperature and humidity on a global scale: higher transmission rates were associated with lower temperatures and humidity.

The researchers further analyzed how this association between climate and disease evolved over time, using a statistical method specifically designed to identify similar patterns of variation in different "time windows."

According to the scientific institution, the first epidemic waves decreased as the temperature and humidity increased and the second wave increased as the temperature and humidity decreased.

By adapting the model to analyze transient correlations at all scales in countries in the southern hemisphere, where the virus arrived later, the same negative correlation was observed.

"These findings support the view of covid-19 as a true low-temperature seasonal infection, similar to influenza and the more benign circulating coronaviruses," said Xavier Rodó.

This possible seasonality of covid-19 recommends “better internal ventilation” of spaces, stressed the study coordinator, who also highlights the need to include meteorological parameters in the evaluation and planning of measures to control the virus.