Warmer and humid weather alone is unlikely to halt the spread of coronavirus, new research has found. Climatic conditions may play a role once larger populations have developed immunity from future outbreaks, it says.
A peer-reviewed study by researchers from the Princeton University doesn’t foresee hot summer making a significant reduction in Covid transmissibility, at least in the current wave of the pandemic.
“Our findings suggest, without effective control measures, strong outbreaks are likely in more humid climates and summer weather will not substantially limit pandemic growth,” noted the study published in the Science journal on Monday.
The researchers warned that global populations are still vulnerable to the virus.
No considerable change from local climatic conditions is noticed in the current rate of infection, the study found.
The researchers used simulations in three different scenarios on how the global pandemic would respond to various climates across the globe.
Their model is based on historical data associated with seasonal variations on the spread of similar viruses in the past — influenza virus, human coronavirus HKU1 and human coronavirus OC43.
HKU1 and OC43 usually cause mild to moderate upper-respiratory tract illnesses, like the common cold.
The study put the novel coronavirus under three imaginary scenarios separately to determine whether it has the same level of climate sensitivity as its cousins in each case.
The research did not look into the individual behaviour of Covid-19 under varying temperatures and humidity levels.
The results showed climate had a mitigating impact only when a large portion of the population already had some kind of immunity or resistance to the virus — which in the case of Covid-19 is not yet there.
“We project that warmer or more humid climates will not slow the virus at the early stage of the pandemic,” observed Dr Rachel Baker, the lead author. “The virus will spread quickly no matter the climate conditions.”
In the absence of interventions, such as vaccination or physical distancing, the virus spread is not likely to slow down in the southern hemisphere, the research noted.
Once a sizable population becomes immune to the virus, the novel coronavirus may start behaving like other human coronaviruses, which are more frequent in winter, it said.
The researchers suggest that the trajectory of Covid-19 over the next several months will be influenced by multiple known and unknown factors, such as social-distancing measures, immune response, and “its strength and duration” in the human population followed by the infection.
The Princeton study was supported by Cooperative Institute for Modelling the Earth System, the Princeton Environmental Institute, and the Princeton Institute for International and Regional Studies.
A global effort to study immune response to the coronavirus spread is still underway.