University of Chicago Medicine begins recruiting participants for phase 3 COVID-19 investigational vaccine clinical trial

Photo courtesy of Janssen

The University of Chicago Medical Center will be a testing site for the Janssen Pharmaceutical Companies of Johnson & Johnson’s Phase 3 clinical research study, ENSEMBLE trial, to evaluate the safety and efficacy of the Janssen’s investigational COVID-19 vaccine candidate, JNJ-78436735, also known as Ad26.COV2.S.

The Phase 3 randomized, double-blind, placebo-controlled clinical trial is designed to evaluate the safety and efficacy of a single vaccine dose of the Janssen COVID-19 vaccine candidate versus placebo, in approximately 60,000 adults 18 years old and older, including significant representation from those that are over 60.

The trial will include those both with and without comorbidities associated with an increased risk for progression to severe COVID-19.

UChicago Medicine will enroll up to 2,000 adults aged 18 and older from within the Chicago community.

“We are looking for individuals from all walks of life to participate in this study,” said trial leader Habibul Ahsan, MD, Director of the Institute for Precision and Population Health at UChicago Medicine. “This includes healthy adults, but also individuals with comorbidities, all genders, older adults, and people of all races. We want to be sure that the community our hospital serves is well represented in this trial.”

To support the recruitment process, Janssen has developed the ENSEMBLE Study website where people interested in volunteering for the study can register. All registration information will be collected, handled and stored according to the local laws and regulations. Following registration, the research centers will evaluate volunteers’ information and then potentially request physical tests before the volunteer is included in the study. The ENSEMBLE website also brings details on the trial, such as medical monitoring and a questions and answers section.

Janssen has joined other pharmaceutical companies in making a pledge to the world that it will continue to adhere to its high scientific, ethical and regulatory standards and will rely on robust clinical evidence to guide the development of its investigational COVID-19 vaccine candidate. Janssen is committed to transparency and sharing information related to the Phase 3 ENSEMBLE study — including the study protocol.

Janssen’s investigational COVID-19 vaccine leverages Janssen’s AdVac® technology. The same technology was used to develop Janssen’s European Commission approved Ebola vaccine regimen and is the basis for its HIV, RSV and Zika vaccine candidates. To date, more than 100,000 individuals have been vaccinated with a Janssen AdVac®-based vaccine.

ENSEMBLE is being initiated in collaboration with the Assistant Secretary for Preparedness and Response (ASPR), Biomedical Advanced Research and Development Authority (BARDA) and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).

This project has been funded in whole or in part with Federal funds from the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under Other Transaction Agreement HHSO100201700018C.

More information about the trial is available at

Individuals in the Chicago region who are interested in participating in the COVID-19 vaccine trials — including potential new vaccine candidates in future trials — may sign up for the UChicago Medicine COVID-19 Vaccine Registry at

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