Immune Response to Vaccines in Immunosuppressed Patients

Freddy Caldera, DO, MS (left), is a formally trained clinical investigator, gastroenterologist, and physician scientist who specializes in inflammatory bowel disease (IBD). 

Mary S. Hayney, PharmD, MPH (center), is a professor at the University of Wisconsin School of Pharmacy.

Their lab primarily evaluates immune responses to vaccine in patients with inflammatory bowel disease (IBD) to determine if certain patients with IBD disease can benefit from a different immunization schedule than the general population.

Inside the Caldera/Hayney lab

Influenza Vaccines

The lab previously found in a randomized clinical trial that the high-dose influenza vaccine induces higher antibodies compared to the standard dose influenza vaccine in immunosuppressed patients with IBD. These results suggest patients with IBD may benefit from receiving a high-dose influenza vaccine.

Dr. Freddy Caldera talks with Dr. Mary Hayney.

COVID-19 Vaccines and Beyond

During the COVID-19 pandemic, Drs. Caldera and Hayney launched the "HumoRal and CellULar initial and Sustained immunogenicity in patients with IBD (HERCULES)" clinical trial. They found that patients with IBD are able to mount antibodies and cellular immune response despite being on immunosuppressive therapy.

As new IBD treatments emerge, or new vaccines—such as the RSV vaccine—are approved, the lab aims to evaluate immune response on these new therapies and determine if patients with IBD need a different immunization schedule for new vaccines.

Laboratory Capabilities

Located on the 4th floor of Rennebohm Hall, the Caldera/Hayney lab is is well-equipped for vaccine-induced immune response studies. It has biologic safety cabinets, centrifuges, ultracold freezers, plate readers and other standard lab equipment. Routine assays for the lab include ELISA, ELISPOT, hemagglutination inhibition assay, cell culture and microneutralization.

Active Projects


This clinical study looks at the immune response to COVID-19 vaccines in patients with inflammatory bowel disease (IBD). 

Patients with IBD are often treated with immunosuppressant drugs. Certain immunosuppressants, such as steroids, may increase the risk of a severe outcome from COVID-19. Studies have also shown that certain medications may blunt the immune response to certain vaccines. This study involves blood draws from patients to examine the immune system response after vaccination by evaluating antibodies and T cells.


  • We evaluated the antibody response after two doses of COVID-19 vaccines and found that 95% of patients made antibodies after two doses of mRNA vaccines. 
  • We evaluated the antibody response of a third coronavirus disease 2019 messenger RNA vaccine dose in patients with inflammatory bowel diseases. All patients made antibodies and they were higher after the third dose than after completion of the 2-dose series.
  • We evaluated antibody concentrations 6 months after a third coronavirus disease 2019 messenger RNA vaccine dose in patients with inflammatory bowel diseases. Almost all patients had an antibody response, and those with a previous SARS-CoV-2 infection had higher antibody concentrations.
  • Antibody and T-cell responses to coronavirus disease 2019 vaccines in patients with inflammatory bowel disease do not correlate. Most patients with inflammatory bowel disease mount a T-cell response despite being on biologic therapies, those on anti-tumor necrosis factor may have a higher T-cell response. Anti-tumor necrosis factor therapy has been associated with a lower antibody response to coronavirus disease 2019 vaccines, but the T-cell response is augmented.
Immunogenicity of Herpes Zoster Subunit Vaccine in Inflammatory Bowel Disease Patients Treated With Vedolizumab

The purpose of this study is to determine the immunogenicity of the herpes zoster subunit vaccine in inflammatory bowel disease patients on vedolizumab compared to those on anti-tumor necrosis factor (TNF) monotherapy.

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Sustained Humoral and Cell-Mediated Immunogenicity of COVID-19 Vaccines in Patients With Inflammatory Bowel Disease

The aim of this study is to determine the impact of systemic immunosuppression on sustained antibody COVID-19 concentrations in patients with IBD who received a COVID-19 vaccine.

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Additional Recombinant COVID-19 Humoral and Cell-Mediated Immunogenicity in Immunosuppressed Populations

To determine whether providing a recombinant booster COVID-19 vaccine improves sustained humoral and cell-mediated immunogenicity against SARS-CoV-2 in immunosuppressed patients with Inflammatory Bowel Disease (IBD) and/or solid organ transplant recipients. 120 participants will be enrolled and can expect to be on study for 6 months.

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Determining the Relationship Between Gut Microbiota and Immune Response to Influenza Vaccine

This study will evaluate the effect of the microorganisms in the gut on how well the flu vaccine works in people who have a weakened immune system due to inflammatory bowel disease. Participants can expect to be in the study for 1 month.

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Funding Support

Dr. Caldera's research is funded by medical society and pharmaceutical industry grants.

Photo of female scientist in white coat holding tray of specimens

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