Q+A: WHAT FACTORS ARE ASSOCIATED WITH DISPARITIES IN COVID-19 VACCINATION RATES?

By Greg Richter | May 5, 2022

Throughout the COVID-19 pandemic, experts from Drexel University’s Dornsife School of Public Health have researched disparities in testing, vaccination, health care access and other markers of the pandemic response. The latest study, this month in the American Journal of Epidemiology , harkens back to December 2020 through September 2021, when the United States first started distributing the COVID-19 vaccines, and looked at full vaccination rates in neighborhoods of 16 large U.S. cities, including Philadelphia, Austin, San Francisco, Chicago and New York City.

Researchers at Drexel’s Urban Health Collaborative used the CDC’s Social Vulnerability Index – a measure that includes socioeconomic, housing, minority status, language and other factors to assess a community’s resilience against human suffering and financial loss when faced with a crisis – and looked at its association with COVID-19 vaccination in zip codes of the 16 cities. The team found wide disparities in vaccination, with neighborhoods with higher levels of social vulnerability having the lowest vaccination rates.

Shortly after the paper was published, Anthony Fauci, MD, the U.S. President’s chief medical advisor, made a comment this week that our country is no longer in a pandemic, but a “transitional phase ,” perhaps toward endemicity.

So, with a hopeful tone, the Drexel News Blog checked in with the paper’s lead author Usama Bilal, PhD , an assistant professor at Dornsife, about his team’s recent findings and the current state of the pandemic locally and internationally.

In December 2020, the U.S. averaged more than 200,000 new cases and just under 2,500 deaths per day. Now we’re at roughly 51,000 new cases per day and 362 deaths. From a numbers standpoint, things seem better. But of course, human lives are not numbers. How you would describe the state of the pandemic in the U.S. right now—and perhaps the state of it globally?

We are in a better situation than one year ago, but we are still in a tough one. 362 daily deaths for a year is 132,000 deaths, which is the same number of people that died from Alzheimer’s in 2019 , and almost thrice the influenza/pneumonia deaths in 2019. The pandemic has also slowly moved further away towards the margin, affecting more rural and disadvantaged populations over time. Moreover, as a pandemic is a global phenomenon, it is still raging in many places, and will continue doing so at least until we achieve global vaccine equity.

What’s the role found between social vulnerability markers, such as socioeconomic status and household makeup and disabilities, and likelihood of full vaccination (two shots of a mRNA vaccine or one shot of the Johnson & Johnson vaccine)? Were you surprised by this finding?

We found that neighborhoods with higher levels of social vulnerability had lower likelihood of full vaccination. This pattern mirrors what we have described before with COVID-19 itself, which tends to be higher infection rates and its effect worse in those same areas. Given what we know about public health, that it affects the most vulnerable, poor and oppressed, this is not surprising. What was surprising is the degree of variability, as we found cities with much wider disparities than others.

You found some cities with narrow or even nonexistent disparities in vaccine inequities. Do you have any examples of things specific cities, such as those in California, did well to increase vaccination? Are there lessons other cities can learn to increase vaccination among those of lower socioeconomic status?

We found that some cities in California, along with our own city of Philadelphia had a narrower gap between neighborhoods. We did not study factors driving these narrower inequalities, but we know that California has an extensive COVID-19 equity plan and that some of its cities (e.g., San Francisco) made an effort to vaccinate people in the more vulnerable neighborhoods.

Here in Philadelphia, there have been several efforts that would be great to evaluate and, if found to be effective, scale up in other locations, including the efforts of the Black Doctors COVID-19 Consortium, the coordinated efforts of community organizations to vaccinate Latino individuals, and some prioritization efforts towards low vaccinated zip codes in April 2021, when criteria for vaccination was more restrictive. We cannot know for sure with our data whether these efforts were the reason for Philadelphia’s narrower gap in vaccination, but they are definitely very important initiatives.

When the vaccines first came out, they were widely heralded by public health experts as a critically needed innovation to turn the tide against COVID-19. Did public health experts underestimate the resistance to getting vaccinated?

Many people that work in vaccines and communication were already talking about this at the beginning of the vaccination rollout, because these are issues we have seen with other interventions. If you think about the politization of mask use, vaccines have followed a similar trend.

However, I want to point out that we should not just focus on hesitancy and mistrust, but also on access. In many cities, getting an appointment to be vaccinated was challenging, vaccination sites were far away from where many people live and public transit options were scarce. There were also some immigrant populations being (incorrectly) asked for identification or insurance, which created very understandable concerns.

As the U.S. approaches 1 million deaths from COVID-19, and a recent JAMA report suggests that COVID deaths worldwide could be three times higher than the reported numbers, what message would you share to readers looking for guidance, or even hope, to endure through yet another COVID-19 variant?

Public health is a collective effort, and its measures are collective by nature. Local public health departments, local and state governments, and the federal government itself, are the key agents driving public health measures. There has been a slow shift towards focusing just on “personal responsibility,” which is antithetical to the mission of public health. Pressuring your local governments to apply timely and adequate measures in times of high transmission, and supporting them when they do, may be a key strategy. If the last two years have taught us something, it’s that caring for each other is the only way out of this.

Media interested in talking with Bilal should contact Greg Richter, news manager, at or 215-895-2614.


This article was originally written by Greg Richter for the Drexel University News Blog.