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Ongoing COVID-19 booster vaccine clinical trial seeks vaccinated volunteers

01/11/2022Media Inquiries

Carrie Bebermeyer
Public Relations Director
carrie.bebermeyer@slu.edu
314-977-8015

Reserved for members of the media.

A clinical trial is testing the safety, tolerability and immune responses stimulated by different doses of investigational COVID-19 second-generation booster vaccines manufactured by Gritstone bio, Inc. 

Dan Hoft, M.D., Ph.D., director of the Center for Vaccine Development

Daniel Hoft, M.D., Ph.D.,  director of the Saint Louis University Center for Vaccine Development, pictured with members of his lab.

Researchers at the Saint Louis University Center for Vaccine Development are continuing to enroll volunteers in an investigational COVID-19 booster vaccine trial. Volunteers will participate in the second (booster) stage of a phase 1 vaccine trial. Phase 1 vaccine trials are designed to test the safety and tolerability of, and immune response to new investigational vaccines.

The study is recruiting COVID-19-vaccinated persons who have not yet received a booster vaccine against SARS-CoV-2, the virus that causes COVID-19.

The Gritstone second-generation vaccines are different from current vaccines. They are designed to elicit an immune response to multiple SARS-CoV-2 proteins, in addition to the spike protein targeted by currently available vaccines made by Moderna, Pfizer-BioNTech and Johnson & Johnson.

By targeting several coronavirus proteins, the investigational vaccines may provide enhanced protection against a wide variety of SARS-CoV-2 strains and variants. The vaccine candidates were developed by Gritstone bio, Inc., a biotechnology company headquartered in Emeryville, California. In monkey models of COVID-19 infection, the vaccine protected against experimental infection and resulted in high levels of antibodies.

“We need to continue to develop new COVID-19 vaccines that can protect against all future SARS-CoV-2 variants that develop, and the Gritstone vaccines have the potential to protect against future variants and provide an additional form of protection by inducing more T cell responses,” said Daniel Hoft, M.D., Ph.D., professor of medicine, molecular microbiology and immunology, and director of the Saint Louis University Center for Vaccine Development and protocol chair of the Gritstone trial.

Getahun Abate, M.D., Ph.D.

Getahun Abate, M.D., Ph.D., SLU Vaccine & Trial Evaluation Unit (VTEU) site principal investigator and associate professor in the division of infectious diseases, allergy and immunology at SLU.

According to Getahun Abate, M.D., Ph.D., SLU Vaccine & Trial Evaluation Unit (VTEU) Site Principal Investigator, great strides have been made in the fight against COVID-19.

“However, because the virus is changing to become more transmissible and sometimes more deadly, we should not lose focus and should continue our endeavors to bring forth improved vaccines,” said Abate who is also associate professor in the division of infectious diseases, allergy and immunology at SLU. "We want new vaccines that give protection against circulating and newly emerging strains as well as provide a long-lasting immunity. To achieve these goals, we need volunteers who have already received COVID-19 vaccines to participate in this ongoing vaccine study at Saint Louis University.” 

To enroll, participants must be age 18 or older, healthy, without significant allergies, without a history of prior SARS-CoV-2 infection and have been vaccinated against COVID-19 at least four months prior to enrollment. Persons over the age of 60 are encouraged to participate. 

Participants will be asked to: 

Interested participants should contact the Saint Louis University Center for Vaccine Development at:

For more information about the trial, visit ClinicalTrials.gov The study’s Clinical Trials Identifier is NCT04776317

The study is sponsored and funded by the U.S. National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and is being conducted through the NIAID-supported Infectious Diseases Clinical Research Consortium (UM1AI148452).