The University of Arkansas for Medical Sciences is recruiting participants for a Phase 3 clinical trial for a COVID-19 vaccine developed by Johnson & Johnson’s Janssen Pharmaceutical Cos.

The randomized, double-blind trial, dubbed ENSEMBLE, will evaluate the efficacy and safety of the vaccine, Ad26.COV2.S. The company is enrolling about 60,000 adults age 18 and older. Participants will be in the study for up to two years and three months and will be randomly assigned to one of two groups, one receiving the drug and the other a placebo, both as intramuscular shots. Janssen has been investigating a one-dose regime in its first Phase 3 trial; it is now also investigation a two-dose regime.


The trial needs volunteers who are most likely to be exposed  to the virus, such as health care workers, first responders, school employees and prison workers. They’ll receive a stipend of up to $1,430 in reimbursement for time and travel.

To enroll, call 501-231-4852. Participants will meet with health professionals over the course of the trial at Freeway Medical Tower, 5800 W. 10th St. After potential candidates register, they’ll be evaluated by health professionals, who will decide whether they should participate. The trial will include persons with and without underlying medical conditions that make them more vulnerable to the novel coronavirus.


Unlike Pfizer and Moderna’s vaccines, which use messenger RNA to provoke an immune response, Johnson & Johnson’s vaccine employs an adenovirus engineered to carry coronavirus genes.  The company paused the trial in mid-October after a participant developed an unexplained illness, but resumed it 11 days later. (AstraZeneca also paused a trial of its vaccine after a participant developed transverse myelitis, but restarted the trial after about a month and a half.)

The Johnson & Johnson vaccine is stable in a refrigerator, an advantage over the Pfizer vaccine, which requires ultra-cold storage.


The U.S. government, which supported the development of the vaccine as part of Operation Warp Speed, has agreed to pay $1 billion for 100 million doses of Johnson & Johnson’s vaccine if it is approved. The company has said it will produce a billion doses next year.