Iowa City Darwin Day: Science Fest 2026
For nearly two decades, Iowa City’s Darwin Day: Science Fest has brought people together each year to celebrate progress across many fields of science. This year’s event, held from April 9-11, focused on vaccines—their pioneers, history, effectiveness, and the forces that shape public trust. Programming on April 10 and 11 took place at the East Biology Building and at Phillip Hall, each of which featured a vaccine clinic, information booths, and expert presentations. Speakers included Aaron Scherer, MA, PhD, UI Carver College of Medicine Associate Professor in General Internal Medicine and Tara Smith, PhD, Professor in the College of Public Health at Kent State University.
The third presenter was Peter Hotez, MD, PhD, DSc, Dean of the National School of Tropical Medicine at Baylor College of Medicine, a pediatrician-scientist at Texas Medical Center, and author of several books about vaccination and science literacy. Hotez is perhaps best known, especially to many in the Darwin Day audience, for his public messaging and media appearances countering misinformation during the height of the COVID-19 pandemic.
Rethinking vaccine messaging
Scherer researches the psychology of medical decision-making, aiming to create evidence-based tools for productive health messaging about issues like vaccination. In his first presentation on April 10, he challenged the conventional approach to vaccine promotion, arguing that simply correcting misinformation can deepen resistance among those already skeptical. The real problem, he said, is that current models assume everyone processes information the same way, which ignores how psychological motives shape peoples’ interpretation of health messages.
Scherer shared a framework with four main motivational drivers for vaccine confidence: threat management, uncertainty reduction, social goals, and information preferences. He described ongoing CDC-funded research that investigates which drivers predict vaccine attitudes. The ultimate goal, then, is to develop messaging strategies that address people’s motivations.
His second presentation, held the next day in Phillip Hall, laid out specific strategies for having productive conversations about vaccinations. First, he covered the learning systems and the cognitive and social biases that influence how people receive and process health information. Next, he discussed approaching these conversations with curiosity—listening to understand rather than rebut—before sharing your own perspective on the topic.
[Related: Scherer was interviewed by both Iowa Public Radio and KCRG-TV]
Pioneers and early misinformation campaigns
Smith, a former faculty member at the University of Iowa College of Public Health, began her presentations by exploring how public fears about vaccine safety developed, spread, and persisted.
Smith examined how a 1974 London study linking the pertussis vaccine to neurological complications triggered media alarm, falling vaccination rates, and the rise of advocacy groups concerned with alleged vaccine injuries.
A re-analysis of medical data found most alleged cases of vaccine-induced encephalopathy were mischaracterized, and the 2001 discovery of the gene responsible for Dravet syndrome explained many remaining cases. Smith closed by acknowledging that statistics alone rarely counter emotionally driven misinformation, and that honest messaging paired with personal storytelling is essential for public trust.
Smith’s second presentation tracked the development of the Pertussis vaccine, made possible by two pioneering scientists—Pearl Kendrick and Grace Eldering. Despite limited resources, Kendrick and Eldering conducted large-scale field traials that proved the vaccine’s effectiveness and ultimately slashed whooping cough cases by thousands.
Pandemic outlook, vaccine promise
Hotez opened with an assessment of global pandemic risk and the causes behind the increase in their frequency, predicting a third SARS event before 2030. He attributed thefrequency of pandemics in part to climate change, which has extended active cycles of insect-borne disease-vectors, as well as increasing population density in urban areas. Still, Hotez did not deploy a defeatist approach, highlighting that the science to combat pandemics exists. The great obstacle, he said, is misinformation.
Hotez’s second talk—the final presentation of Darwin Day—reinforced why the fight is worth having. Citing WHO data, Hotez noted that since 1954, global vaccination efforts have averted 154 million deaths and added 10.2 billion years of life across the world—an illustration of what investment in vaccines can achieve.
