Inside a Phase 3 Vaccine Trial

By Christopher Sullivan | February 12, 2021


Recent news reports have revealed that a third COVID-19 vaccine may soon be available.  Johnson & Johnson, and its subsidiary, Janssen Pharmaceuticals, have been developing a single shot COVID-19 vaccine that can be stored in a regular refrigerator.  

I’ve been following this development closely because last November, I signed up to be a trial participant for the Janssen Phase 3 trial, known as the ENSEMBLE trial.  After reading about the recruitment effort in the news, I filled out the volunteer form and was accepted. The vaccine trial has recruited around 42,000 volunteers from Argentina, Brazil, Chile, Colombia, Mexico, Peru, South Africa, and the United States with an emphasis on at risk and older populations.   

Being involved in a vaccine trial of this importance, even as minimal as my participation is, has not only been hugely informative, its been a bit exciting. The process that trial participants go through is quite impressive.

After applying and being accepted the same day, the local test site reached out to schedule an initial screening and medical exam. The initial screening appointment took about two hours. Locally, the ENSEMBLE trial is being conducted through a partnership with St. Jude, University of Tennessee, and Methodist Healthcare.  From the outside, the local facility seems like something out of a disaster response headquarters, which in a way it is. A series of drab, tan, portable buildings in a parking lot on the north end of Downtown Memphis belies the ultra modern medical facility inside. 

The initial screening was about as involved as qualifying for life insurance but more thorough. A thirty plus page booklet of disclaimers greets new trial participants, along with a whirlwind of screening questions, temperature checks, blood pressure checks, height and weight measurements, nasal swabs, and blood draw. As many as five or six different people from the intake person, tech guy, lead researcher, and other personnel review your information, explain what you are getting into, what the trial participants are required to do, what they can’t do, etc.

Then its time to get stuck. “Show time” as it were. The ENSEMBLE trial is blind, so the participants and researchers do not know who is getting the experimental vaccine and who is getting the placebo. While the shot itself is no more concerning than any other shot in terms of how it feels, you can’t help but feel more than a little apprehension about the whole thing. The mechanism of J&J vaccine is tried and true, having been used in the Ebola, Zika and HIV vaccine studies over several years and tens of thousands of participants, but still, this vaccine for this purpose is not yet approved by the FDA.      

Of course, afterward, I felt nothing but for the rest of the day, the slightest sensation immediately caused me to think the worst, that I’m the one in a million instances where there is an adverse reaction. Fortunately, that was not the case. Its been almost three months and I never felt any reaction of any kind.  Of course, anecdotally, that means I got the placebo, but really, it doesn’t mean anything. Everyone reacts differently. That said, I’m assuming I got the placebo but who knows?

Being a vaccine trial participant does create a bit of a dilemma when my time comes to get an approved vaccine. If I already received a vaccine, is there any harm of getting another on top of it? But how do I know? Fortunately, with the urgency to just get as many people vaccinated as possible, trial participants are now being told that if you get an appointment for a vaccine, let the study team know and they will decide whether to unblind you so that you can know whether you are doubling up or not vaccinated at all.    

Going forward, for the next two years, I have to check in twice a week through an app, make periodic visits to be evaluated, and if I do develop symptoms, there’s a whole protocol akin to Major Kong taking inventory of his survival kit.  Aside from the sweet tote bag, free pulse oximeter, and de minimis compensation, its worth signing up for a trial like this. I’m not saving anyone’s life but collectively, I’d like to think it helps end the pandemic a little sooner.   

If you want to get into the weeds about study, trial participants, and the efficacy of this vaccine, visit:

Johnson & Johnson Announces Single Shot

Share this: