Summer heat won’t kill the coronavirus, but it can change it, experts say
It’s time to put the myth to rest: You can catch the novel coronavirus no matter how sunny or hot the weather is, and it will continue to spread through summer.
The durability of the coronavirus in warmer weather is a message public health agencies have been spreading since the pandemic began, but leaders across the country still sporadically tout the myth as one that could save millions from infection, stress and fear.
The catch? Although there is no evidence that summer heat can kill the virus in a way that leads to less infections and deaths, it can mutate it, and that’s not necessarily a bad thing.
What’s more, the majority of a population in a region must have some level of immunity before weather can play any role in slowing or speeding things up, research shows.
“When things get hot, [the virus] is exposed to heat that can encourage it to mutate, make itself more adaptable and have better fitness to withstand that new temperature,” Dr. Andria Rusk, an assistant professor specializing in infectious disease at Florida International University’s College of Public Health and Social Work, told McClatchy News.
But such mutations have only been observed in laboratories, leaving doubt if they would occur in natural settings.
“I don’t know that there’s any evidence of coronavirus responding to the change in the seasons in this ambient climate change temperature kind of way and causing a mutation. It’s not that it isn’t happening, but I don’t know if there’s any evidence that it is happening.”
Think of it from a Darwinian perspective, Rusk suggests. Viruses just want to survive as best they can so they can continue to make copies of themselves.
“It’s like we have Xerox machines in each of our cells and the virus will hijack our machines and use it for their own purposes” — and the more often they do that, the more the virus mutates, she said.
“SARS-CoV-2 [the virus that causes COVID-19] is no exception to that,” Rusk added.
Meanwhile, research has shown that high temperatures can mutate the coronavirus’ genetic material while proving hostile for a virus’ survival.
One study found that after 30 minutes under 133 degrees Fahrenheit, coronavirus particles were no longer viable, according to a paper published in April in the journal The Lancet Microbe.
“This is exclusively, though, in a laboratory setting,” Rusk said. “So, you’re talking about direct heat, you’re not talking about ambient climate change, like spring to summer climate change.”
Still, such findings do not imply people are free from infection while basking in the sun; that’s because the virus is inside of us where the sterilizing ultraviolet light cannot reach.
The evidence lies in real time case counts from steaming hot regions such as Florida and Texas, both experiencing spikes in coronavirus cases, and Brazil, which is the second worst-hit country with over 1.6 million confirmed cases after the U.S, according to Johns Hopkins University’s COVID-19 tracker.
And because these extremely high temperatures don’t exist on Earth, experts are left with a foggy understanding of whether an 80-degree summer will have the same effect.
People need immunity before other changes can occur
One research team found that humans’ lack of immunity to the coronavirus will continue to drive rapid spread of the disease through the summer and into the fall — and not the weather.
“Those earlier studies focused on well-known human infectious diseases,” Dr. Francis Collins, a physician-geneticist and director of the National Institutes of Health, wrote in a blog. “Less clear is how seasonal variations in the weather might modulate the spread of a new virus that the vast majority of people and their immune systems have yet to encounter.”
The research team ran computer simulations on how the virus will spread in the coming months and every model showed that “climate only would become an important seasonal factor in controlling COVID-19 once a large proportion of people within a given community are immune or resistant to infection,” Collins wrote.
And even if the coronavirus is found to be as sensitive to climate as influenza or the common cold, heat will still not play a large enough role in slowing down viral spread, according to the study published in May in the journal Science.
“One should not assume that we are going to be rescued by a change in the weather,” Dr. Anthony Fauci, the nation’s leading epidemiologist, told ABC’s Good Morning America back in April. “You must assume that the virus will continue to do its thing.”
And do its thing it will.
This story was originally published July 7, 2020 at 1:34 PM with the headline "Summer heat won’t kill the coronavirus, but it can change it, experts say."
