According to a recent Brazilian study, the transmissibility of SARS-CoV-2 decreases significantly until the temperature reaches 25.8 degrees Celsius. Above 25.8°C (78.44°F), the level of infectiousness of COVID 19 stabilizes. This leads us to believe that summer heat may help us reduce the number of cases and slow down the spread, still without our collective preventative actions it alone will not be able to stop the epidemic.
We all hope that the epidemic will abate on its own and become a distant memory. However, there is great uncertainty in this regard. If we can immediately put to one side the categorical discourse of scientists who claim that the second wave is science fiction, we may wonder what role the arrival of summer temperatures could play in the epidemic. A recent Brazilian study suggests that this could help us. But without social distancing and the recommended precautions, we should not expect any miracles.
Up to 78.44°F, the rise in temperature could reduce the transmission of the disease
We know from Florian Gouthière’s excellent article that a cold and dry or hot and very humid environment favors the transmission of flu viruses. For cold viruses usually benign coronaviruses, the cold and dry environment seems to be the most important environmental factor favoring their spread. We can therefore assume that SARS-CoV-2 will leave us alone this summer. It may bring us some relief, but it’s probably not going to stop circling on its own.
In a recent Brazilian study, researchers found that every 1 degree Celsius increase from 16.8 to 25.8 degrees Celsius reduced the transmission of SARS-CoV-2 in cities with a subtropical climate by 4% per degree Celcius. Above 25.8°C, the transmission rate stabilizes. We can, therefore, expect that a small temperature increase may limit SARS-CoV-2 transmission this summer, although what was observed in this study is only a correlation and a number of climatic factors differ between subtropical cities in Brazil and US cities. We should not, therefore, rely on this. Social distancing and following the recommendations of the CDC will be of the utmost importance.
The importance of social distancing
As we have seen, we should not expect miracles if, compared to everything we know about other coronaviruses and some studies here and there, we can expect a little help from the heat. To continue to contain the epidemic, it is important to remember that the best way to reduce the transmission of a virus is to keep your distance, wash your hands regularly, cough on your elbows, and wear a mask properly.
Day after day, this new virus surprises us, not always in a positive way. Humbly considering the worst possible scenarios seems to be the right solution.