Recently, Dr. Robert Redfield, the Director of the Centers for Disease Control and Prevention (CDC), announced that a second wave of the coronavirus pandemic could coincide with the flu season and put an enormous strain on the health care system.

In an interview with The Washington Post, Redfield shared, “There’s a possibility that the assault of the virus on our nation next winter will actually be more difficult than the one we just went through. And when I’ve said this to others, they kind of put their head back, they don’t understand what I mean.”

“We’re going to have the flu epidemic and the coronavirus epidemic at the same time,” he said.

The death toll for the coronavirus in the U.S. already stands at more than 45,000 and infections are at a staggering 826,000 confirmed cases.

Authorities have also revised the first coronavirus death in the U.S. from February 29 in Kirkland, Washington to February 6 and 17 in Santa Clara County, in Northern California. What’s quite frightening about this reevaluation is that the patients who died had not traveled to China, which meant the disease was already spreading within the community without the knowledge of local officials. This was discovered because the Santa Clara County Medical Examiner sent tissue samples to the CDC for testing after conducting the autopsy.

It’s difficult to imagine the outbreak getting much worse, but history tells that a potentially deadlier second wave is not entirely outside the realm of possibility.

During the 1918-1919 Spanish Flu pandemic, there were not one but three waves of the disease, and the second was by far the deadliest. And, so far at least, it appears like the coronavirus may be following a similar path.

Historically, the flu has been around for thousands of years, though the first pandemic occurred in 1510. So, it wasn’t a big surprise when the first cases of the flu were reported in a military base and a public health publication in Kansas in the Spring of 1918. But the severity of it was slightly unusual, and a sign of things to come.

Though the first wave took a toll on the usual suspects, the elderly, young children and the infirm, that all changed in the fall of 1918. As a result of the disease mutating, the second wave was exceptionally deadly and attacked young healthy adults between the ages of 20-40. This phenomenon is called a “W-curve,” and is a distinct epidemiological pattern that has only been documented during the Spanish Flu. It has never been seen again.

The second wave lasted only three months, between September and November, but it killed 195,000 Americans in just the month of October. That’s 29% of all the American Spanish Flu deaths reported in the U.S.

The third wave of the pandemic started in January 1919 and lasted throughout the spring and early summer before finally dying out. Scientists eventually determined that the particular strain of the flu that infected 500 million people and killed between 20-50 million was a strain of the H1N1 flu, also known as the swine flu.

So, what does all of this mean for us living during the coronavirus pandemic? Unfortunately, if Dr. Redfield is right, there will be a second wave and perhaps even a third. And if the disease potentially mutates into a more deadly strain, which kills faster and more efficiently, we may be doing this stay-at-home thing once again in the fall.

That’s a scary prospect, but a great reminder that it’s important to continue following the protocols of social distancing, wearing masks and being aware that though things may slow down in the summer, the fight might not be over.