COVID-19 Control Measures Still Needed During Warm Temperatures
Cooler weather and higher population density were linked with higher transmission.
A recent study conducted by investigators from Imperial College London, in collaboration with Utah State University, has found that the transmission of COVID-19 varies seasonally, but warmer temperatures alone are not enough to prevent the spread of the virus.
Findings from the study were published in the journal Proceedings of the National Academy of Sciences.
"Our results show that temperature changes have a much smaller effect on transmission than policy interventions, so while people remain unvaccinated, governments mustn't drop policies like lockdowns and social distancing just because a seasonal change means the weather is warming up,” Tom Smith, lead author on the study said.
Counting the number of cases between countries and regions on a global scale is difficult because of the differences in interventions and population densities.
For the study, the team of investigators analyzed transmission data from across the United States due to the fact that the country has a large range of climates with comparable policies and case numbers.
Findings showed that there was strong evidence that showed lower temperatures and higher population density are both associated with higher SARS-CoV-2 transmission.
These two factors are the most important in terms of transmission, but only when mobility-restricting measures, such as lockdowns, are not in place.
"We found evidence that, in the early phases of the pandemic, places with colder temperatures were associated with higher SARS-CoV-2 transmission intensities. However, the effect of climatic seasonality on SARS-CoV-2 transmission is weaker than the effect of population density and in turn, of policy interventions,” Ilaria Dorigatti, an author on the study said. "This implies that, as we move towards summer in the Northern Hemisphere, public health policy decisions remain of critical importance for epidemic control and adherence to recommendations will continue to play a key role against SARS-CoV-2 transmission."