The Problem of False Equivalency in Public Health Debates

We should stop giving credence to bad ideas.

Posted Oct 21, 2020

In a free and open society, debate is important. But there is a danger in too strong a belief in the idea of an open forum, where unsound thinking from fringe elements may be given the same standing as educated and informed opinions.

This week I was given the opportunity to appear on national television to debate one of the scientists behind the White House’s herd immunity policy—a policy I have compared to mass murder. I have been quite outspoken about this pointless and ineffective strategy. Based on our current understanding of coronaviruses as a whole and SARS-CoV-2 in particular, there is no evidence that herd immunity exists for this disease. Pursuing such a policy is a tragedy in the making, one which could kill more than 2 million Americans in the coming months. The head of the WHO called it unethical. The former head of the CDC called it a catastrophe. And I have yet to hear of any serious scientist or public health official who endorses the approach.

While some may have jumped at the opportunity to publicly debate the merits of the approach, I declined the invitation: I do not believe in giving credence to false ideas. I didn’t come to this belief easily, though. I, like many of you, once believed quite deeply in the importance of open debate, even with those who hold diametrically opposing views. While I may not have been quick to believe the latest conspiracy theory, I felt it was worth hearing out those who did, and worth the attempt to convince them otherwise. But my feelings have changed over the years.

In the 1980s, I and a small team of scientists were working to identify the cause of a new and troubling disease, which we now know as AIDS. Eventually, we identified the virus that caused the disease, HIV, and we came to understand that anyone could be infected—gay, straight, drug user or not. But there were others who doubted this thinking, including one prominent scientist and former mentor who questioned the role of the virus in causing AIDS. He suggested instead that AIDS was caused by long-term recreational drug use and the use of antiretroviral drugs.

He was wrong, and I and my other colleagues knew it. But instead of pushing his thinking to the side, I engaged him publicly in the debate—in journal articles (found at nature.com), public lectures, and in the media. But the debates did not achieve what I hoped it would, which was to convince those who believed in his thinking that they were wrong. All I achieved was giving a broader stage to a false viewpoint.

It is hard to put a number on how many died unnecessarily because of the popularity of that scientist's approach. But there is no doubt that political leaders used his words to justify inaction. In South Africa, former president Thabo Mbeki refused to acknowledge the scientific consensus and instead bought into the words of AIDS denialists like those I debated. Mbeki’s refusal to recognize the scientific consensus on HIV and AIDS was directly responsible for the avoidable deaths of more than a third of a million people in that country.

Today, President Trump is doing the same with herd immunity and COVID-19, using it as a post facto justification for his previous inaction and current unwillingness to implement the public health measures—social distancing, mask-wearing, contact tracing, and quarantine—that are guaranteed to save lives.

Now, as then with AIDS, many will die as a result of a belief in an unfounded and dangerous hypothesis. Now, like then, a falsehood is being adopted as truth by national leaders for reasons grounded in political expediency, not a desire to control the pandemic. Herd immunity is not an option, and never will be. To equate the sound public health measures we know will work with the fantasy of one day achieving herd immunity is a false equivalency. As scientists, we are trained to accept that any hypothesis can have value. But when we speak of hypotheses we speak of educated assumptions. When it comes to herd immunity and COVID-19, the approach has no value.