Yes, the CDC can change its mind

The Nobel Laureate economist Paul Samuelson famously acknowledged in a Meet the Press interview: “Well when events change, I change my mind. What do you do?” This observation applies to the advice from medical authorities such as the CDC and WHO during the COVID pandemic. Some members of the public are fond of pillorying these agencies for having published different guidelines at different times, as though health officials are in the business of issuing ex cathedra dogma rather than responding to incomplete and ambiguous information. Science doesn’t deal in proof, it deals with the weight of evidence. A scientific hypothesis is one that is capable of being tested and falsified by experiment.

I get it. I used to teach problem-based learning to first year medical students, and they often struggled with what to do with incomplete and ambiguous information, which is what physicians in clinics do every day. Sometimes, one cannot wait for all the tests to be completed and all the data analyzed before taking some action. With new evidence, a change in action is sometimes warranted.

Thanks to COVID, the curtain on research and discovery has been pulled away and the omniscient Oz is revealed to be a mere mortal doing their best with the resources at hand. So when new and better data appear, it is right and responsible to examine previous advice in light of those data. This happens all the time, even if most people don’t see it. As the virus and our understanding of its epidemiology changes, the guidance changes.

So rather than prating at the CDC for evolving standards in light of new data as though discovering that papal bull was found to be papal bull****, celebrate the fact that science is self-correcting and, overall, moves towards better understanding. To paraphrase MLK: “the arc of the scientific universe is long, but it bends toward truth.”