Fall and Winter -- COVID-19 Dynamics

"Certain viruses like influenza tend to have a seasonality. Some people think it's humidity. Some people think it's temperature. Some people think it's behavioral, and which of those is most important is not known. Also, do they all matter? That's also not known. So one concern is potentially that if we are indoors more often and more likely to cough on each other — as a result, we could see more in-household transmission."

– Jennifer Nuzzo, senior scholar at the Johns Hopkins Center for Health Security

Some health experts are saying the United States should be looking to the Southern Hemisphere, already deep into its winter season, to see where COVID-19 might be heading in its first full fall and winter since coronavirus was discovered. The unfolding dynamics of the pandemic in southern countries may shed light on how COVID-19 and influenza will interact in the fall.

Earlier this month, Africa passed the 1 million mark for the number of recorded cases of COVID-19. Australia has imposed its second lockdown in Melbourne as cases spiked in key urban areas. The virus's progress in these colder continents could be a precursor of horrors to come.

A search of government statements issued by officials in the United States suggests that little attention is being directed south. Is this a mistake?

David A. Andelman, executive director of The RedLines Project, says …

“There are any number of reasons the coronavirus could be spreading more rapidly in cold weather, but without hard data, scientists are treading gingerly. For one thing, research suggests respiratory viruses seem to transmit more readily and droplets carrying them remain more viable in the winter's cold weather and lower humidity.”

(David A. Andelman. “COVID-19 spikes in South Africa, Melbourne offer America clues ahead of winter 2020.” NBC News Think. August 17, 2020.)

A study by University of Sydney researchers published in the journal Transboundary and Emerging Diseases pointed out "an association between lower humidity and an increase in locally acquired positive cases. Researchers discovered a 1 percent decrease in humidity could increase the number of COVID-19 cases by 6 percent."

Study lead Michael Ward said in a press release …

"COVID-19 is likely to be a seasonal disease that recurs in periods of lower humidity. We need to be thinking if it's winter time, it could be COVID-19 time."

(Michael P. Ward, Shuang Xiao, and Zhijie Zhang. “The role of climate during the COVID‐19 epidemic in New South Wales, Australia.” Transboundary and Emerging

Diseases.May 21, 2020.)

The risk of spreading the coronavirus is heightened in enclosed spaces. Outdoors, there is enough air for the virus to be “rapidly diluted,” as well as the helpful “virus-killing action of sunlight,” explains Linsey Marr, an engineering professor at Virginia Tech. Indoors, “the virus can build up” and be more easily inhaled, and “if the space is heated, it can lead to dry air,” which is more hospitable to the virus.

(Joe Pinsker. “The Winter Will Be Worse.” The Atlantic. August 05, 2020.)

Two Lethal Viruses

Dr. Robert Redfield, current director of the Centers for Disease Control and Prevention, and Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases -- have said they anticipate a big uptick to happen this fall and winter.

Much of the attention aimed at fall has now shifted to concern over the possibility of two potentially lethal viruses circulating at the same time -- COVID-19 and the seasonal flu, the latter of which kills around 40,000 people in the US per year. Because of certain overlapping symptoms such as fever and a cough, it may be harder for individuals and doctors to immediately determine which infection you have.

Dr. Redfield warned …

"The real risk is that we're going to have two circulating respiratory pathogens at the same time … I do think the fall and the winter of 2020 and 2021 are going to be probably one of the most difficult times that we've experienced in American public health."

(Mandy Oaklander. “The Coronavirus Plus the Flu Could Equal a Devastating Fall and Winter, CDC Director Says.” Time. June 29, 2020.)

Flu season in the U.S. usually arrives in October and then peaks from December to February. Joe Pinsker reports that even though researchers don’t yet know how severe this year’s flu season will be, this overlap is worrying for three main reasons:

“First, even in the absence of a pandemic, flu season can tax hospitals’ beds and resources. Having both the flu and COVID-19 spreading at once could further strain an already strained health-care system.

“Second, COVID compromises the respiratory system and so does flu, so each of them makes the other one worse,”

“And third, because the two diseases have some symptoms in common, telling them apart can be difficult. That in turn can hinder efforts in hospitals to identify suspected COVID-19 cases. It also could prompt worry and fear in people who don’t know which disease they’ve come down with.”

(Joe Pinsker. “The Winter Will Be Worse.” The Atlantic. August 05, 2020.)

The U.S. may still be able to avert the most dismal predictions for winter. Ashish Jha, the director of the Harvard Global Health Institute, says …

“I am more optimistic that November, December, January, February are not going to be some kind of apocalypse that looks like what life felt like in March or April. I think we can do better than that. But it will require policy intervention.”

According to Jha, namely: widespread, affordable, and quick testing; strongly enforced masking mandates; and improved ventilation in classrooms and other indoor spaces.

“Anybody who says we are not living in a divisive era in our country is not paying attention, If we can somehow get the country unified together, we could make it into the fall and winter looking good.”

– Dr. Anthony Fauci