Coronavirus: Why it's pointless to define a 'second wave' according to experts - CNET

The coronavirus pandemic's US death toll passed 155,000 people in late July. That's more COVID-19 deaths than the entire European Union combined and orders of magnitude higher than the death toll in most countries around the world. Hotspot states like California and Florida are setting new records. 

But is this the first wave of COVID-19 infections or the second? And what happens when flu season arrives? Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, says we're still "knee deep" in the first wave because confirmed case numbers haven't dropped far enough for long enough to squash the initial outbreak. 

Then there's Dr. Michael T. Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota. He told MarketWatch the wave theory doesn't apply here. "We've never had a pandemic due to coronavirus before," he said. In other words, expect the unexpected.

But there could be an even bigger threat looming. "The real risk is that we're going to have two circulating respiratory pathogens at the same time," warned Dr. Robert Redfield, director of the Centers for Disease Control and Prevention, when he spoke to Time Magazine regarding the upcoming flu season.

We take a look at what doctors and scientists have to say about a second wave of the coronavirus, including how it might relate to the current spike in new cases as well as what experts predict for the fall and winter. Please note: This story provides an overview of the current discussion, and is updated frequently in light of new and changing information provided by health officials, global leaders and the scientific community. It is not intended as a medical reference.

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Global coronavirus pandemic: The latest news

• Speaking to Congress July 31, Fauci said he remains "cautiously optimistic" that the US will have a safe and effective vaccine by the start of 2021.
• In almost half of US states, new cases have finally leveled off and, in some areas, actually started trending down.
• The Midwest could soon see a surge of coronavirus cases, according to Fauci, who identified Ohio, Indiana, Kentucky and Tennessee as the next potential hotspots during a July interview with Good Morning America. 

• Total historical US coronavirus cases are now surpassed 4.5 million at the end of July, including over 2 million active cases.
  

• Statewide lockdown measures vary tremendously across the US, with about a third of states pausing reopening, a third reversing course and a third fully or almost fully reopened.

If we're still in the first wave, when will a second wave happen?

The first wave will end when the rate of positive coronavirus tests drops to "the low single digits," Fauci said in June. Basically, you can't have a second wave until cases and deaths from the first wave drop close to zero for a sustained period of time. If cases spike again after that point, that's a bona fide second wave. 

Several countries in Asia that had successfully beat back the coronavirus to single-digit numbers have begun seeing new cases again, leading some to consider the current trend in Hong Kong, Vietnam, South Korea and China a true second wave. 

The World Health Organization, however, continues to sidestep the term "second wave," choosing tofocus less on how the pandemic's inflection points are labeled and more on what steps countries need to take to reverse course toward fewer cases and deaths.

Why do coronavirus cases go up and down so much?

At one point, about 90% of everyone in the US was under some sort of lockdown order and the curve was starting to flatten. But that all began to change in the second half of April, when a few states started loosening lockdown restrictions. By June, most of the country had almost fully reopened. Not long after, new cases began to surge once again.

Epidemiologists are starting to identify a correlation between lockdown and case levels. Basically, wherever you look, cases drop when lockdown orders are issued -- and shoot back up right after restrictions start lifting. The only thing that seems to disrupt the trend is how well an area's population adheres to disease prevention measures like wearing face masks and limiting social gatherings.

Sweden, for example, was able to flatten the curve without going into full lockdown. Instead, Swedes for the most part changed their behavior without the government ordering them to. They left home and gathered in numbers less frequently -- and wore masks and practiced good hygiene when they did. In July, CDC director Redfield said, "I think if we could get everybody [in the US] to wear a mask right now, I think in four, six, eight weeks we could bring this epidemic under control."

Why are experts worried about coronavirus in the fall?

Most public health experts -- including Fauci and Redfield -- have said they anticipate a big uptick to happen this fall and winter. The White House has admitted it's preparing for the possibility. However, part of that prediction was based on the assumption that the virus would slow down over the summer, which appears not to be happening.

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.

If severe COVID-19 infections continue to push hospitals to the brink of their capacity and abilities, it may also be harder to care for potentially virulent flu patients.

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The CDC is nudging drug manufacturers to produce millions more doses of flu vaccine this year than usual in anticipation of greater demand. Typically, fewer than half of all US adults take the flu vaccine in any given year, but that rate increases to about two out of three for adults over 65, a population the CDC has identified as being at a higher risk for more severe COVID-19 infections.Are we headed for another lockdown?

Are we headed for another lockdown?

Health experts, including Fauci and Dr. Ali Khan, the former director of the CDC's public health preparedness office, have said that if states are able to effectively test for coronavirus -- and follow that testing up with contact tracing -- while people in those states practice social distancing and wear masks in public, it would be possible to once again flatten the curve without having to revert back to a full-blown lockdown. If that strategy isn't followed and new cases continue to skyrocket, "your only option is to shut down," Khan said.

More than likely, we will see various levels of lockdown come and go in different areas, depending on where the virus flares up and dies down, until we find a coronavirus vaccine. Even then, however, we might not be in the clear just yet. Osterholm opines, "We will be dealing with this virus forever. Effective and safe vaccines and hopefully ones with some durability will be very important, even critical tools, in fighting it. But the whole world is going to be experiencing COVID-19 'til the end of time."