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The economy is plummeting, and tens of millions of Americans need to get back to work. But at what cost?

We know there are health consequences to keeping the economy closed, and some say thousands of Americans are at risk of “deaths of despair.”

But as states try to balance saving lives and saving livelihoods, experts say some arguments for reopening the economy now are short-sighted or flawed. Here are some examples:

ARGUMENT: Keep the elderly at home, but let young or healthy people go back to work

Studies suggest 25% to 50% of coronavirus carriers don’t have symptoms. But asymptomatic carriers can still infect others, including the more vulnerable.

There’s actually a “huge swath” of young people who have underlying conditions, such as obesity, respiratory diseases, autoimmune disorders and “unprecedented” levels of type 2 diabetes, said Dr. Greg Poland, an infectious disease professor at Mayo Clinic in Minnesota.

Even young people who are otherwise healthy can suffer severe complications. Their strong immune systems can overreact to the virus, a phenomenon doctors call cytokine storms.

“I just want to make sure everybody knows that no matter what their age is, it can seriously affect them. And it can seriously mess them up, like it messed me up,” said Dimitri Mitchell, 18.

The Iowa teen said he might have contracted the virus while working at a grocery store. His condition deteriorated so badly, he needed to be hospitalized. His mother said she worried he might “fall asleep and never wake up.”

“I just hope everybody’s responsible, because it’s nothing to joke about,” the teen said. “I want everybody to make sure they’re following social distancing guidelines and the group limits. And just listen to all the rules and precautions and stay up to date with the news and make sure they’re informed.”

ARGUMENT: We didn’t shut down the economy for SARS or swine flu

Unlike SARS and swine flu, the novel coronavirus is both highly contagious and especially deadly, CNN Chief Medical Correspondent Dr. Sanjay Gupta said.

“SARS was also a coronavirus, and it was a new virus at the time,” Gupta said. “In the end, we know that SARS ended up infecting 8,000 people around the world and causing around 800 deaths. So very high fatality rate, but it didn’t turn out to be very contagious.”

The swine flu, or H1N1, “was very contagious and infected some 60 million people in the United States alone within a year,” Gupta said. “But it was far less lethal than the flu even — like 1/3 as lethal as the flu.”

What makes the novel coronavirus different is that “this is both very contagious … and it appears to be far more lethal than the flu as well,” Gupta said. “So both those things … are why we’re taking this so seriously.”

It’s impossible to pinpoint the exact death rate for Covid-19. On one hand, the death rate could be much lower if there are many survivors who never got tested.

On the other hand, researchers say the outbreak started earlier than previously thought, meaning it’s possible early deaths from Covid-19 were never diagnosed as such.

As of May 11, more than 4.1 million people around the world have been infected, and more than 284,000 have died, according to data from Johns Hopkins University.

ARGUMENT: The flu kills more people every year, and we don’t shut down the economy for that

Coronavirus has actually killed more people in three months than the flu did in six months.

The US death toll from coronavirus this year has exceeded 79,000, according to Johns Hopkins.

That’s more than the high-end estimate for flu deaths from October 1 to April 4, which is 62,000, according to the Centers for Disease Control and Prevention.

If 62,000 people died from the flu between October 1 and April 4, according to the CDC’s high-end estimate, that means the US had an average of about 331 flu deaths a day.

The first known coronavirus death was in February, and the death toll as of April 30 was 62,850, according to Johns Hopkins data.

So from February 6 through April 30, an average of more than 739 people died per day from coronavirus in the US.

ARGUMENT: Just let everyone get herd immunity the natural way

That’s a “dangerous calculation,” said Dr. Mike Ryan, executive director of the World Health Organization’s Health Emergencies Programme.

Herd immunity happens when the majority of a certain population – typically 70% to 90% – becomes immune to a disease, either because they’ve already been infected or because they’ve been vaccinated.

At that point, the disease is less likely to hit people who aren’t immune because there aren’t enough infectious carriers to reach them.

But many doctors say lifting all restrictions and letting coronavirus spread rampantly is a terrible idea.

First, hospitals would likely be overwhelmed, jeopardizing the health of coronavirus patients as well as non-coronavirus patients.

“The advantage of stretching out the number of cases is that we will not exceed the capacity of hospitals to care for those who are particularly sick,” said Dr. H. Cody Meissner, chief of pediatric infectious disease at Tufts University Medical School.

Then there’s the devastating loss of life. By May 11, more than 79,000 people in the US have already died, according to data from Johns Hopkins University. That’s more than the number of Americans who died in the Vietnam War.

“This idea that … so what if we lose a few old people along the way? This is a really dangerous, dangerous calculation,” Ryan said.

ARGUMENT: Cases are still increasing, so social distancing doesn’t help anyway

Social distancing has definitely helped decrease the rate of transmission, researchers say. But letting up too early can backfire, just like it did in other parts of the world.

Without mitigation efforts (like stay-at-home orders), a person with novel coronavirus infects an average of about 2 to 3 other people.

(By contrast, a person with the flu infects an average of about 1.28 other people, and there’s a vaccine available to help prevent infections.)

But after stay-at-home orders were enacted, the rate of transmission fell below 1 in many states, said data scientist Youyang Gu, whose coronavirus projection model is cited by the CDC.

“The ultimate goal is the to keep the basic reproduction number under 1,” Gu said.

A reproduction number under 1 means fewer and fewer people will get infected, and the virus will start fading away. But a rate of more than 1 means the outbreak will get worse, spreading exponentially.

“If a state can keep their R level below 1, their numbers will continue to decrease.”

What happens after a state reopens will likely depend on how rapidly the virus was spreading right before.

“If your R value is 0.95, it’s unlikely you can maintain a value of under 1 after you reopen,” Gu said.

But states that had much better R values will have more leeway, even if more people get exposed to the virus in public.

“If you go from 0.8 to 0.9, you’re still going to decrease” the overall spread, Gu said.

Each person can also help control the outcomes as states start to reopen.

Officials recommend everyone continue staying 6 feet away from others, wear a cloth face mask outside the home, wash hands frequently and avoid touching the face.

According to recent studies, Gu said, “If any state required all residents to wear masks, the likelihood of a steep increase in infections will decrease.”

You asked, we’re answering: Your top coronavirus questions

CNN’s Amanda Watts, Alicia Lee and Arman Azad contributed to this report