Natural variations in ultraviolet radiation (UV) influence the spread of Covid-19, but the influence is modest compared to preventive measures such as physical distancing, mask-wearing, and quarantine, say researchers.
“Understanding the potential seasonality of Covid-19 transmission could help inform our response to the pandemic in the coming months,” said study author Jonathan Proctor from the Harvard University in the US.
These findings, published in the journal Proceedings of the National Academy of Sciences, suggest that the incidence of Covid-19 may have a seasonal pattern, spreading faster in the winter when it is darker than in the summer.
Analysing daily Covid-19 and weather data from over 3,000 administrative regions in more than 170 countries, the research team found that the spread of Covid-19 through a population tended to be lower in the weeks following higher UV exposure.
The seasonality of Covid-19 has been a mystery since the disease first emerged one year ago, though there have been some clues that UV could play a role.Related species of coronaviruses such as SARS and MERS were found to be sensitive to UV radiation and recent laboratory studies show that UV inactivates SARS-CoV-2, the virus that causes COVID-19, on surfaces.
Attempts to understand the influence of UV in the real world, however, have been limited by scarce data and the difficulty of isolating climate variables from other drivers of transmission. (IANS)
