When Experts Polarize: Offit, RFK Jr., and the CDC's Covid Vaccine Shift

Epistemic humility in an age of scientific polarization

Yesterday, venerated vaccine expert Paul Offit published a forcefully black-and-white perspective on this week’s CDC guidance change from recommending Covid vaccination for healthy kids and pregnant women to no longer recommending it (“RFK Jr.’s War on Children”).

Covid vaccination for healthy young people, especially males, may risk net harm due to possible vaccine side effects like myocarditis. We don’t know and may never know, since we don’t have randomized trial data comparing post-infection versus post-vaccine outcomes, and it wouldn’t be ethical or practical to conduct such trials.

Long-term safety for the new mRNA technology is another unknown. Critics including leading medical methodologist Peter C. Gøtzsche and investigative journalist Maryanne Demasi have also expressed concerns about underreported Covid vaccine trial harms. Reports of shoddy manufacturing standards including contamination concerns have been widespread since the beginning of the rushed pandemic vaccination production process.

Similarly, evidence suggests substantial possible increased risks of stillbirth and birth defects associated with Covid vaccination in pregnancy. The truth is, we don’t know how the net harm-benefit balance tips. It likely depends on how well a woman is able to choose to avoid infection, since we need to know if we’re comparing infection with versus without vaccine risks, or no infection versus no vaccine risks. That’s a complex set of possible risks it might be best for a patient and her doctor to weigh, instead of a blanket recommendation blunting these unknowns into a binary.

Offit concludes: “Although the data are clear, [RFK Jr.] chooses to ignore them.”

But the data on this are subject to a great deal of uncertainty and interpretation, as they are in much of science. There is no exit from being a human being with limited cognitive-emotional hardware and perspective. This is particularly salient when one interprets complex, ambiguous scientific evidence.

What bias?

Offit’s perception of the CDC vaccine guidance change is likely distorted by his vocal, reasonable concern about RFK Jr.’s questionable handling of measles outbreaks and MMR vaccine promotion (or lack thereof). Vaccine misinformation threatens children’s lives worldwide, including in the U.S., due to the resurgence of preventable diseases like measles.

In a pair of books I recently reviewed, investigative journalist Brian Deer has established that Andrew Wakefield was a fraud; Wakefield is the subsequently de-licensed British physician-researcher who proposed the MMR vaccine caused autism, sparking a global wave of parental vaccine hesitancy and subsequent measles outbreaks. Gøtzsche has argued that vaccines are like drugs, each with its own risks and benefits to assess; on the basis of his assessment of the evidence, he suggests everyone should get the MMR vaccine, but healthy young people should indeed not get Covid vaccines. (I critiqued his excellent vaccines book here.)

The fact that leading experts can disagree about how to interpret the best available evidence on vaccines, including those for Covid, suggests that the issue is complex, multiple possible interpretations may be reasonable, and suggesting that one’s opponents in related policy debates are engaged in a “war on children” does not advance civil engagement about where uncertainties lie, what they mean, and how policymakers and parents can best make informed choices.

Broader context

The second Trump Administration has been busy shaping science. Scientists generally seem to be against it; there’s been a lot of vocal criticism of things like defunding bias research, DOGE’s cost-cutting spree, and last week’s Executive Order on science reform. Some of it has a reasonable basis. Much of it seems to be bandwagoning, or a reaction carried over from fear that the Administration’s other policies and actions (e.g., in law enforcement) are sliding into authoritarianism.

These dynamics reflect a deeper problem: Scientific discourse is political. Dissenting views are often punished rather than debated.

Unfortunately, hyperpolarized criticism like Offit’s is likely to have a further chilling effect on scientists’ already limited ability to express dissenting views. It also risks alienating moderates and people who haven’t made up their minds. It diminishes his considerable credibility, though his reaction is understandable as a product of outrage over preventable child deaths from measles.

The cost to the public interest is higher than that to his reputation. We need room for disagreement, skepticism, and evidence-based pluralism in medical and scientific discourse. Room for dissenting views to be held by reasonable opponents. Not monsters waging a war on children.