Splashy news coverage of the first wave of COVID-19 clinical vaccine trials has triggered a similarly high-profile debate about “Who Should Be First?” to get the vaccine when it does become available. But there is one equally important question being asked much less frequently: What happens if not enough people get vaccinated to establish the herd immunity crucial to ending the pandemic and returning the country and its economy to some semblance of “normal?”
National Institute of Allergy and Infectious Diseases Director Anthony Fauci acknowledged the first versions of a COVID vaccine would only be 70-75% effective. He went on to say that level of effectiveness, paired with the fact that one-third or more of the U.S. population doesn’t intend to get vaccinated, makes it “unlikely” the U.S. will reach sufficient levels of herd immunity.
“It is a serious problem,” emphasizes Penn professor at the Annenberg School for Communication and the School of Engineering and Applied Science Damon Centola, who specializes in network analysis. “Vaccine hesitancy has become politicized and, as a result, increasingly entrenched within specific communities. The model of herd immunity works if a small number of unvaccinated individuals are randomly distributed throughout a population,” he says. “But if the members of a particular community coordinate on choosing not to vaccinate, then the entire community is vulnerable to an epidemic outbreak.”
“We have a large amount of both information and misinformation flowing across four levels of discourse—scientific, political and practice, news, and social media,” says Penn epidemiologist, vaccine hesitancy expert and LDI Senior fellow Melanie Kornides. “It becomes very hard for the public to discern which information is credible and which is not. This is increasingly difficult when political leaders give contradictory, and sometimes dangerous, advice.”
Carmen Guerra, LDI senior fellow and vice chair of Diversity and Inclusion in the Perelman School of Medicine's Department of Medicine, testified in July before a committee of Pennsylvania State senators investigating the impact of coronavirus infections throughout the region’s African American communities. “We have staff and experiences in the community that already tell us there’s misinformation circulating that makes many of our Black residents fearful of a COVID vaccine; makes them mistrustful of a vaccine.”
In a recent article, fellows Katherine Milkman, Mitesh Patel, and Angela Duckworth examine how behavioral economics principles might be brought to the task of increasing COVID vaccination rates. “The good news is we don’t have to start from scratch,” they write. “We already have scientifically-tested ways to encourage people to make healthier decisions, and there are many more approaches to encouraging vaccination that haven’t been tested.”
Read more at Penn LDI.