Humidity, high temperatures may delay but cannot stop coronavirus spread

New Delhi : A new study has revealed that humidity and high temperatures can only delay and not stop the spread of coronavirus, adding to a growing body of literature that indicate that the correlation between local climate conditions and virus transmission is weak.

The study was conducted by scientists at Princeton University and the US National Institutes of Health and published in the journal Science on Monday. It suggests that the lack of immunity and speed of pathogens ensured that the climate has a little role to play in spread of the virus.

"It doesn't seem that climate is regulating spread right now," said Rachel Baker, a postdoctoral scholar in the Princeton Environmental Institute and first author of the paper. "We project that warmer or more humid climates will not slow the virus at the early stage of the pandemic."

Earlier, the studies during the initial stage had raised hopes that the countries with hot climates may see decline in coronavirus spread.

But this paper joins previous research from the Massachusetts Institute of Technology and the US National Academies of Sciences (NAS) that say while there is some evidence that Sars-CoV-2 transmits less efficiently in higher ambient temperature and humidity, this does not lead to a significant decrease in disease spread without major interventions, such as personal protection and social distancing.

The scientists ran three scenarios. The first assumed that coronavirus has the same climate sensitivity as influenza. The second and third scenarios assumed the virus had the same climate dependence as OC43 and HKU1, which cause common cold and are of the same betacoronavirus genus as Sars-CoV-2.

In all three scenarios, climate became a significant factor when large portions of the population were immune or resistant to the virus. "The more that immunity builds up in the population, the more we expect the sensitivity to climate to increase," Baker said.

Talking about the practicality, it has been seen that the places like New York, London and Delhi, which have different temperatures did not show any significant difference in pandemic size.

It has been claimed that currently, only immunity or a discovery of a vaccine can people protected from the coronavirus.

"Our simulated control measures imply that the key determinant of reduced peak incidence is the extent to which population immunity builds over the control period...the timing of introduction and the efficacy of local control measures as well as factors such as population density and contact patterns could also shape future outcomes," the study said.