The false promise of ‘herd immunity’ to beat COVID-19
If the United States were to throw open the economy and bet on creating herd immunity without a vaccine, the death toll could run into the hundreds of thousands.
We’re all eager to get back to our old lives.
This social distancing stuff sure grows old, and our jobs, our kids’ education and our national economy are on the line.
But as Anthony Fauci, the nation’s top infectious disease expert, stressed at a Senate committee hearing on Tuesday, reopening the country before the COVID-19 pandemic is better under control could lead to unnecessary “suffering and death” and might even “turn the clock back” on an economic recovery.
Fauci, in his usual cordial way, was sending a not-so-subtle warning of possible disaster to states that are pushing right now — with President Trump’s encouragement — to reopen in major ways.
“My concern is we would start to see little spikes that [turn] into bigger outbreaks,” Fauci warned. “There is a real risk that you would trigger an outbreak that you will not be able to control.”
False promise of herd immunity
Central to the argument of many proponents for an immediate reopening of the country is that doing so would lead to the quick building of herd immunity among Americans, slamming the brakes on the spread of the virus. As Americans came down with COVID-19 and recovered — if they did not die — they would become immune to catching the bug again or passing it on.
But an array of medical experts have poured cold water on that notion in recent weeks, including Fauci on Tuesday. While it is “very likely” that people who have recovered from COVID-19 enjoy “a degree of protection,” Fauci said, nobody yet knows how intense or prolonged an exposure to the virus is necessary to gain immunity or how long it lasts.
Nor, he said, do we yet understand the full and long-term effects of the virus. He noted, for example, that doctors have just recently discovered the virus can cause “a very strange inflammatory syndrome” in children.
In order for Americans to develop herd immunity, experts say, an effective vaccination against the coronavirus must be developed, and the earliest that might happen is late fall or early winter.
In the meantime, what are we to make of supposed expert medical advice from the likes of radio talker Rush Limbaugh, who’s all for throwing open the country and pursuing herd immunity right now?
To take them seriously is to risk running out of coffins.
“Without a vaccine, over 200 million Americans would have to get infected before we reach this [immunity] threshold,” Johns Hopkins University epidemiologists David Dowdy and Gypsyamber D’Souza wrote recently. “If current daily death rates continue, over half a million Americans would be dead from COVID-19 by that time.”
Worldwide, 40 to 50 million people would likely die if countries decided to try and achieve herd immunity without a vaccine, University of Chicago associate professor Luis Barreiro, author of a recent study on herd immunity, told us.
“It’s completely irrational to consider that as an option,” Barreiro said.
Gov. J. B. Pritzker last week called it “an invitation for us to just let people die.”
How herd immunity works
A country or community achieves herd immunity to a disease once a sufficiently high percentage of people are immune to it. That occurs either from vaccination — the process experts overwhelmingly recommend — or by recovering from a disease and developing antibodies to it.
The small percentage of individuals who are not immune, such as those who cannot be vaccinated for medical reasons, are then protected. There’s little or no chance of them catching the disease since the vast majority of people are immune.
The necessary level of herd immunity for a particular disease depends on how contagious it is. Measles, for instance, is highly contagious; each person who contracts the disease infects, on average, 12 to 18 more people. Herd immunity for measles, experts say, requires a vaccination rate of 95%.
Based on what scientists know so far about the coronavirus that causes COVID-19, at least 70% of the population would have to be immune to reach herd immunity.
In theory, we could reach that threshold by letting people contract the disease and recover, Barreiro told us. But, he said, millions of Americans — perhaps 3 million — would die. Millions more would require hospitalization, straining the healthcare system to the breaking point. Still more people then would die of other afflictions, like cancer and heart disease.
“Pretty much everyone would have someone in their family dying,” Barreiro said.
Don’t follow Sweden
Fans of herd immunity strategy, without a vaccine, like to cite the example of Sweden, where the government has imposed only a partial lockdown. While the death rate in Sweden from COVID-19 is higher than in other Scandinavian countries, it is lower than in many other European countries. Most travel and mass gatherings have been banned, but businesses, bars and restaurants are allowed to remain open.
The United States, however, is not Sweden.
Americans, on average, are far less healthy than Swedes, to begin with, and much more likely to be obese. They run a considerably higher risk of death, rather than recovery, from COVID-19.
Sweden’s approach also has exacted a painful price. The virus has swept mercilessly through retirement communities, running up a high rate of death among elderly Swedes.
The United States had better continue to put its faith in science — and look before it leaps.
Or this plague will come roaring back.
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