As the United States continues to scramble to open back up the country and reinstate a sense of normality, some experts, including leading coronavirus expert Dr. Anthony Fauci, are already warning of a so-called “second wave” of the coronavirus pandemic.
In other words, we may see a surge of COVID-19 again in the fall, after the spread of the disease slows and falls dormant in the summer months. Given what infectious disease researchers have surmised—as well as what history has taught us—this seems like a very real possibility. But as with many aspects of this disease, there’s still plenty that medical professionals are still learning.
What can we do to prevent a fall resurgence?
CDC director and virologist Dr. Robert Redfield said that the agency is preparing “most likely” for another anticipated wave in the late fall or early winter, in which we would see that a substantial portion of Americans is still susceptible. “Hopefully, we’ll aggressively re-embrace some of the mitigation strategies that we have determined had an impact, particularly social distancing,” Redfield said in early April.
On April 21, Redfield told the Washington Post that a second wave next winter could be even worse than the first wave the world is currently experiencing, because people could be battling the coronavirus and the seasonal flu at the same time.
“There’s a possibility that the assault of the virus on our nation next winter will actually be even more difficult than the one we just went through,” Redfield said. “And when I’ve said this to others, they kind of put their head back, they don’t understand what I mean.”
One of the biggest factors that will determine if and how greatly the virus will spread in the fall and winter is the availability of antibody testing, which will help virologists understand the extent of infections that have already occurred in our country.
“It will give us a much more accurate understanding of the symptomatic vs. asymptomatic ratio, and will give us a much better understanding of the mortality, once we see the full extent,” Redfield told NBC News on April 13. “Also, it can be useful in defining high-risk populations that are conceptually immune.”
However, Redfield adds: “I think it’s important to emphasize that we haven’t yet proven that once you develop antibodies, [you develop protective immunity]. It’s still a scientific hypothesis that this virus will lead to protective immunity of some duration.”
The risks of opening up the U.S. too early
Dr. Ben Cowling, an epidemiology professor at the University of Hong Kong’s School of Public Health, told CNBC that by lifting current restrictions on social distancing too early, countries run the risk of unleashing a second wave of infections.
“I think having timelines is going to be very challenging. No country is going to want to open up too early, and then be the first major country to have a big second wave,” said Cowling. “It’s going to be very difficult because we know that even countries that overcome their first wave, they’re going to have challenges from other countries who are still experiencing their first wave or even experiencing a second wave, which could be starting now in China.”
Cowling adds that he believes testing will be critical, but there will still be a need for social distancing, to an extent, even in June or July.
Have we already hit a second wave?
According to Kent Sepkowitz, an infectious disease specialist for Memorial Sloan Kettering Cancer Center, the U.S. has technically already passed a second wave and is now actually on its fourth wave.
Sepkowitz believes the first wave of coronavirus in the U.S actually occurred on the West Coast after a Washington state nursing home became ravaged with the disease. The second wave then hit New York City—which remains the country’s current epicenter—where more than 110,000 patients have since been infected.
From there, the third wave of coronavirus spread to urban “hot spots,” such as New Orleans, Detroit, and Atlanta. By April, Sepkowitz argues that a so-called fourth wave of the virus had begun infiltrating mid-sized and smaller cities, previously believed to be not dense enough to spread the virus.
For example, Cleburne County in rural Arkansas, home to a scant 26,000 people, saw more than 60 people infected as the possible result of a church outing.
“It is highly likely that we will have—I don’t know whether you want to call it a second wave—but we will have a return of infections as we get into the next season,” Fauci said of the virus’ progression.
What we can learn from the flu epidemic of 1918
The flu epidemic of 1918, which infected 500 million people worldwide over the course of two years, saw the most fatalities during the second wave of the virus—which eventually claimed approximately 50 million lives. Some researchers believe the original spread of the virus can be attributed to U.S. troops being deployed en masse for World War I efforts across Europe in the spring of 1918, where they carried that influenza virus with them.
The virus then spread like wildfire through England, France, Spain, and Italy. However, the first wave of the flu was not particularly deadly and lasted approximately only three days in an infected person with symptoms such as fever and malaise.
Historians now believe that the bulk of the flu fatalities occurred during the “second wave” in the fall of 1918, which was caused by a mutated virus spread across by troops.
“The rapid movement of soldiers around the globe was a major spreader of the disease,” Ohio State University historian James Harris, who studies both infectious disease and World War I, told History.com. “The entire military-industrial complex of moving lots of men and material in crowded conditions was certainly a huge contributing factor in the ways the pandemic spread.”
It’s worth noting, however, that the rapid spread of flu in the fall of 1918 was at least partially to blame on the refusal of global public health officials to impose wartime quarantines, Harris says—from troops to civilians, such as munitions factory workers. To make matters worse, the U.S. saw a severe nursing shortage, as thousands of nurses had been deployed to military camps and the front lines.
Beyond that, science simply didn’t have the tools or understanding to develop a vaccine for the virus, as microscopes with the ability to detect something as small as a virus weren’t invented until more than a decade later in the 1930s.
The third wave of the Spanish flu saw a mortality rate just as high as the second wave, but the end of the war in November 1918 prevented the virus from spreading so easily, and as such, fatalities paled in comparison to the crippling deaths that occurred during the second wave.
At this point, it remains to be seen what kind of results a second wave of COVID-19 would potentially bring to the globe.