Bansal Leads Vaccine Hesitancy Study

Biology professor Shweta Bansal, pictured here in Healy Hall, has been awarded an NIH grant to study trends in vaccine hesitancy.
Biology professor Shweta Bansal has been awarded a National Institutes of Health grant to study trends in vaccine hesitancy. (Georgetown University photo)

October 23, 2017 — With anti-vaccine activists growing in number and influence in recent years, public health professionals have become increasingly interested in identifying where and why people refuse vaccines and how this behavior drives the spread of vaccine-preventable disease. New research spearheaded by a Georgetown College professor may provide them with an invaluable tool.

Shweta Bansal, an assistant professor in the Department of Biology, is leading a team that has been awarded a five-year, $1.7 million grant from the National Institutes of Health to study trends in vaccine hesitancy among Americans.

Bansal — alongside collaborators Pej Rohani of the University of Georgia, Murali Haran of Pennsylvania State University, and Saad Omer of Emory University — will utilize data from health insurance claims to identify areas of the country where vaccine refusal is on the rise. They’ll then use this information to study the emergence and spread of childhood diseases such as measles, whooping cough and chicken pox.

Rates of vaccine refusal are currently tracked at the state level by the Centers for Disease Control, but the diverse makeup of most states makes these numbers not especially useful for policymakers seeking to better understand the geographical trends. Bansal’s dataset includes information at the ZIP code level.

“To tackle the resurgence of vaccine-preventable diseases we first need to understand the distribution of vaccine hesitancy within the country,” Bansal said. “The fine resolution of our data means we can geographically localize this behavior and associate it to social and economic characteristics of an area.”

The team’s preliminary analysis of the socioeconomic profile of vaccine refusers has revealed that the practice is most commonly associated with areas of high education.

“While there is previous work on what motivates individuals to engage in vaccine hesitancy, we don’t know much about the populations that tend to have higher rates of this behavior,” Bansal said. “But public health policy is made at the population-level. And our work will help us understand how to design and target effective population-level policies.”

Bansal and her collaborators also plan to share their findings through an online portal so policymakers may use their data as a surveillance tool.

“Public health decision-makers haven’t had access to high-resolution estimates of vaccination and vaccine hesitancy behavior data,” Bansal said. “We hope our tool will allow federal, state and county public health policymakers to study national and regional trends as well as drill down to focus on their locality.”

Future research funded by the NIH grant will examine the implications of vaccine refusal on measles and whooping cough outbreaks, and will predict future vaccination and disease patterns.

Outbreaks of diseases that had been all but eradicated in the United States have risen in recent years: A case of mumps was reported at Georgetown two weeks ago, for example, and Syracuse University is in the midst of a 40-person outbreak. Public health scholars suspect that outbreaks like these are related to increased rates of vaccine refusal, which eliminates herd immunity and puts those who cannot be vaccinated for medical reasons at increased risk. Bansal’s research will aim to establish a connection between the two trends, and develop predictive models of both vaccination behavior and disease spread.

“We’re looking at how this behavior plays into disease emergence,” Bansal said. “Ultimately, we want to understand this process well enough to forecast it, and, in collaboration with our CDC colleagues, design policy to positively affect vaccination patterns and mitigate disease spread.”

Eventually, Bansal hopes that this research will have an impact beyond U.S. borders.

“Vaccine hesitancy isn’t limited to the US,” she said. “Vaccine-preventable diseases are on the rise in the UK and across Europe, and we hope that our work will ultimately inform local elimination in other developed settings and bring us one step closer to global eradication.”

The research project marks a major milestone for Bansal and Georgetown: It will be housed within the NIH’s prestigious MIDAS (Models of Infectious Disease Agent Study) network, a collaboration among scientists who use data and mathematical modeling to prepare, detect and respond to infectious disease outbreaks.

“MIDAS is a hub of infectious disease dynamics research, and is the network the country turns to get one step ahead of infectious disease threats” Bansal said. “I am honored to be joining this elite community in the important work they do.”

— Patrick Curran