Study Explores COVID-19 Vaccine Effectiveness
The AZ HEROES research study is tracking viral immunity over time and assessing vaccine effectiveness in Arizona essential workers and college students.

University of Arizona Health Sciences
March 3, 2021


University of Arizona Police Chief Brian Seastone gets vaccinated at Campus Health.
University of Arizona Police Chief Brian Seastone gets vaccinated at Campus Health. Chris Richards/University of Arizona

To better understand the complexities of the immune response to the novel coronavirus and evaluate the viral immunity of Arizona essential workers, a University of Arizona Health Sciences research team has been conducting a COVID-19 study since last summer called the Arizona Healthcare, Emergency Response, and Other Essential Workers Surveillance study, or AZ HEROES.  The team recently expanded its efforts to look at how well COVID-19 vaccines are working to provide lasting immunity for high-risk populations.

The first iteration of AZ HEROES was launched by researchers in the Mel and Enid Zuckerman College of Public Health and the College of Medicine – Tucson to test immunity in essential workers – health care workers, first responders and other frontline workers – across Arizona.


Jeff Burgess
Jeff Burgess Kris Hanning/University of Arizona Health Sciences

"The research questions we aim to answer will provide much-needed data for decision making as we continue to confront the pandemic," said Dr. Jeff Burgess, study principal investigator and associate dean for research and a professor in the College of Public Health. "The study results will help us understand how long immunity to COVID-19 persists and if repeat infection is different than initial infection. This information is critical for essential workers as they continue to be exposed to COVID-19 through their work."

Expanding Research Scope

The study's initial goals were to establish patterns of immunity over time in individuals who previously tested positive for COVID-19 and evaluate how common COVID-19 reinfection is among the state's frontline workers.

The study's broadened focus on COVID-19 vaccination effectiveness also includes a large sample of Arizona college students.

"This new vaccine effectiveness aspect of the study will become even more important as COVID-19 variants with increased transmissibility emerge and expand globally," said Burgess, who is also a member of the university's BIO5 Institute.

In addition to evaluating the effectiveness of SARS-CoV-2 vaccines in preventing SARS-CoV-2 infection and COVID-19 illness, investigators will take blood samples from volunteers before and after vaccination against COVID-19 and see how the immune system responds, gathering data that might shed light on the differences between the Food and Drug Administration-approved vaccines and the effect of dosage and timing on vaccine recipients. Researchers will investigate whether sociodemographic characteristics, occupation or health status have significant effects on the vaccine's effectiveness in individuals.

Researchers also will examine whether vaccines make recipients less likely to experience severe illness, even if they were to be infected with the novel coronavirus, and if their illnesses will clear up sooner. They will look at "viral shedding" among essential workers who come into contact with the virus after they have been vaccinated, to see if they can infect others.

The study will also explore essential workers' knowledge, attitudes and practices related to COVID-19 vaccines, and how those factors impact behaviors, including vaccine refusal, hesitancy or incomplete adherence to vaccination recommendations.

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Kate Ellingson
Kate Ellingson Kris Hanning/University of Arizona Health Sciences

"Following the AZ HEROES cohort over time affords us the ability to better understand a combination of epidemiologic risk factors for SARS-CoV-2 infection in essential workers including on-the-job exposures, community exposures, household composition, underlying health, sociodemographic characteristics, and timing of vaccination," said Kate Ellingson, study co-investigator and assistant professor in the College of Public Health.

Participation Continues to Grow

College students can be at higher risk of COVID-19 exposure due to high-density living situations in dormitories or in small spaces with roommates, and may be exposed through social activities or work, volunteer or internship obligations. The investigators hope to enroll 500-1,000 undergraduate and graduate students from Arizona universities and colleges by June.

To date, the AZ HEROES study has enrolled close to 3,000 participants. In addition to college students, the researchers are continuing to enroll health care personnel, first responders and other essential workers who previously tested positive for COVID-19 but have not yet been vaccinated.

"We are truly grateful to the participants in the AZ HEROES cohort, who submit diagnostic specimens and data week after week. In addition to serving our community through the essential work that qualified them for this study, they are supporting scientific advances in our understanding of COVID-19", said Karen Lutrick, co-investigator and assistant professor in the College of Medicine – Tucson.

In addition to Burgess, Ellingson and Lutrick, the AZ HEROES research team includes Dr. Janko Nikolich-Žugich, head of the College of Medicine – Tucson's Department of Immunobiology, co-director of the Center on Aging and member of the BIO5 Institute; Xiaoxiao Sun, assistant professor in the College of Public Health; and Dr. Joe Gerald, associate professor in the College of Public Health.

The AZ HEROES team invites all eligible faculty, staff and college students to sign up for the study on the AZ HEROES website. The current eligibility criteria are as follows:

  • Previously COVID-19 positive via polymerase chain reaction, rapid antigen or antibody test;
  • Have not yet received the COVID-19 vaccine;
  • Work at least 20 hours per week and at least 50% of their job must involve activities that could bring them within 3 feet of other individuals (including members of the public, co-workers or patients), or college student enrolled at least part-time (at least six units) and working at least 10 hours per week.

A version of this article appears on the Health Sciences Connect website:


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Shipherd Reed

Mel and Enid Zuckerman College of Public Health