Why scientists say we can't rush herd immunity - Los Angeles Times
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The coronavirus lockdown is miserable. Rushing herd immunity could be worse

Demonstrators in Huntington Beach protest stay-at-home orders.
(Allen J. Schaben / Los Angeles Times)
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You are so done with this coronavirus lockdown.

You’re tired of Zoom cocktail hours, the never-ending pile of dishes, Netflix.

You miss your friends. You want to hug your parents. You want to see people’s faces, no masks please.

And if you are among the more than 30 million Americans who filed for unemployment since mid-March, you are probably freaking out about your finances too.

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Perhaps you are beginning to wonder if the people protesting stay-at-home orders around the state and across the country have a point: Maybe this extended physical distancing is doing more harm to our collective health than good.

Just how bad would it be to let everyone struggling to pay their bills go back to work? To eat at a restaurant again? To go to the beach on a hot day without being scolded by your governor?

After all, doesn’t this pandemic end with either a vaccine, herd immunity or some combination of the two? If everything reopened and a few more people got sick, might that be a reasonable price to pay?

If only it were that simple.

There is no doubt that there are significant health risks associated with the lockdown. People fearful of going to the hospital or the doctor’s office are delaying cancer treatments, toughing out strokes and heart attacks at home and thinking about skipping their dialysis sessions.

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Studies show that in times of economic hardship suicide rates go up and domestic violence increases. And prolonged physical isolation is associated with an increase in depression, anxiety, irritability and stress.

But for the time being, public health experts say those costs cannot compare with the massive loss of life that would occur if officials decide to throw up their hands and fast-track herd immunity.

As the coronavirus keeps us stuck at home, scientists and health officials fear that social distancing could take a toll on our mental health.

April 29, 2020

Nearly 60,000 Americans died of COVID-19 in April, and that was when physical distancing measures were largely in place across the country.

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By comparison, researchers estimate that the Great Recession that began in December 2007 led to 4,740 additional suicides in the U.S. over the ensuing three years.

Even if you include deaths from other causes that might be tied to a bad economy, “I don’t think there is a great data-driven argument that any recession is likely to cause the same amount of death as we are currently seeing from COVID-19,” said Dr. David Eisenman, director of UCLA’s Center for Public Health and Disasters. “That would have to be examined, but that’s my hypothesis.”

And scientists say that if lockdown restrictions were suddenly lifted, the number of deaths from the virus would skyrocket.

“As a country, we are certainly talking about at least a million deaths if we just reopen and do nothing else,” said Ira Longini, a professor of biostatistics at the University of Florida.

“You can try to do a cost-benefit analysis, but it’s hard to put a dollar value on death,” he said.

Longini’s models suggest that by the end of April, between 3.4% and 6.3% of the U.S. population had been infected with the virus.

Achieving herd immunity would require at least half of the population to have immunity to the virus, and ideally more like 60% to 70%, he said.

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Israeli scientists say they can mimic the effects of a vaccination campaign if certain people willingly get infected with the coronavirus and recover.

April 25, 2020

And it’s not clear that surviving an infection will do much to build herd immunity. Scientists don’t know yet how long immunity to COVID-19 lasts: It could be years, or it could be months. It’s also possible that it might not exist at all.

If the virus acts like other coronaviruses, it’s probable that people will have at least partial immunity for several months after recovering from an infection, but nobody can say that for sure, researchers said.

“The entire concept of herd immunity assumes something about COVID-19 we don’t know is true,” said Summer Johnson McGee, dean of the University of New Haven’s School of Health Sciences. “It’s a dangerous policy to float when we don’t have the immunological information that we need.”

Epidemiologists also caution that the blind pursuit of herd immunity would probably have the gravest consequences for the most vulnerable members of our society.

“We have huge inequities between rich and poor, black and white, and entire swaths of the country without insurance and access to doctors,” Eisenman said. “If we allow this disease to run through the population, it will no doubt take the poor and the most marginalized people in the society.”

In Illinois, Louisiana and Michigan, African Americans are dying at higher rates than whites from coronavirus.

April 7, 2020

It’s for these very reasons that epidemiologists say the United States should not pursue the strategy being carried out in Sweden. The northern European country has chosen not to close schools, restaurants and bars, and is instead relying on “trust-based” measures to control the virus. That includes advising people to work from home if they can, wash their hands regularly and avoid nonessential travel. Compliance, however, is voluntary.

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It may sound like a dream, but health experts point out that the U.S. and Sweden are very different countries. For example, Sweden provides universal healthcare to its citizens as well as subsidized housing and child care.

“We’re not Sweden,” Eisenman said. “They did that in a society that has all these supports for people, and on top of that has excellent infrastructure for staying home.”

That being said, scientists are just as eager as the rest of us to get lockdown measures lifted as soon as possible, and most of them agree that keeping us stuck in our homes until a vaccine is found is not a viable strategy.

“This is something we’ve been discussing internally at the World Health Organization,” said Dr. Michael Ryan, executive director of the WHO’s health emergencies program. “On one hand we have the science, on the other hand we have the practical reality of life.”

Ryan said that until there is a vaccine, we may never reach a point when there is absolute scientific certainty that it is 100% safe for 20 people to be together in the same room — let alone 200 or 20,000.

Creating a vaccine capable of preventing the coronavirus that causes COVID-19 will take many months — if not a year or more. These are the steps involved.

March 12, 2020

Instead, he said government leaders and the communities they serve need to decide what risks they are willing to take and how they will manage the fallout if their risky decisions don’t pan out.

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“This has to be considered on a societal level,” he said. “It has to be based on evidence, but you have to adapt that evidence to the reality of living life.”

Lydia Bourouiba, a professor of environmental engineering at MIT who studies the spread and control of infectious diseases, said the criteria for lifting lockdown measures should not be as strict as ensuring that nobody will be sickened by the coronavirus. Instead, the goal should be ensuring that the number of people who will need to be hospitalized with COVID-19 matches the capacity of local hospitals to care for them.

“The hospitals are really the bottleneck here,” she said.

Shelter-in-place orders have effectively kept many hospital systems across the country from becoming overburdened by COVID-19 patients, but that could change quickly as restrictions are eased.

“Because of confinement, there is an appearance that we can manage this,” Bourouiba said.

But if those measures were suddenly lifted with nothing to replace them, we would overwhelm the healthcare system and doctors would start having to choose who lives and who dies, she said.

“That’s the ethical question people in our society need to be thinking about,” Bourouiba added.

So, what will it take to ease the stay-at-home measures with minimal risk to society? Public health experts agree on the essentials: the capacity to rapidly test people who may be infected, isolate those who test positive, and track and quarantine their close contacts.

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And unfortunately, communities must be willing to go back into lockdown if there is an explosion of cases in their midst.

“We are not going to get rid of this disease anytime soon, so we are going to have to learn to live with it,” Eisenman said.

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