A new, phase three clinical trial for Janssen Pharmaceutical Companies’ investigational COVID-19 vaccine began recruiting adult volunteers this week to see if a single dose could prevent symptomatic cases.
The trial will enroll up to 60,000 volunteers at nearly 215 clinical research sites in the United States and abroad. Janssen will lead the trial as regulatory sponsor, with funding assistance from the National Institute of Allergy and Infectious Diseases (NIAID) and the Biomedical Advanced Research and Development Authority (BARDA).
The new trial marks the fourth phase three clinical trial of a potential COVID-19 vaccine in the United States.
“This is an unprecedented feat for the scientific community made possible by decades of progress in vaccine technology and a coordinated, strategic approach across government, industry, and academia,” NIAID Director Anthony Fauci said. “It is likely that multiple COVID-19 vaccine regimens will be required to meet the global need. The Janssen candidate has showed promise in early-stage testing and may be especially useful in controlling the pandemic if shown to be protective after a single dose.”
Janssen’s vaccine candidate is a recombinant vector vaccine that utilizes a human adenovirus — a kind of virus that causes the common cold — to express the SARS-CoV-2 spike protein in cells. It has been altered to no longer replicate, thereby removing its ability to cause disease. Preclinical findings have shown that the vaccine spurred neutralizing antibodies in rhesus macaques and provided complete or near-complete protection against SARS-CoV-2 infection in the lungs and nose.
The vaccine’s safety, reactogenicity, and immunogenicity must still be assessed, and a phase 1/2a trial in the United States and Belgium is currently enrolling adult volunteers to that end. However, interim results have shown promise.
The phase three trial is being conducted in collaboration with the federal Operation Warp Speed, aiming to accelerate the development, manufacturing, and distribution of medical countermeasures to COVID-19. U.S. and international trial sites from the NIAID-supported COVID-19 Prevention Network will also participate in the trial.
“To have just one candidate vaccine in Phase 3 trials less than a year after a virus was first reported would be a remarkable accomplishment; to have four candidates at that stage is extraordinary,” HHS Secretary Alex Azar said. “By building a portfolio of candidate vaccines, Operation Warp Speed is maximizing the chances that we will have substantial supplies of a safe and effective vaccine—and maybe multiple vaccine options—by January 2021.”
The trial will focus on whether or not the vaccine can prevent moderate to severe COVID-19 cases after a single dose, and determine whether the vaccine can prevent the necessity of medical intervention, as well as milder cases of COVID-19 and asymptomatic infection.