Researchers at Harvard Medical School teaching hospital Beth Israel Deaconess Medical Center reported encouraging interim results Friday from an early clinical trial of a COVID-19 vaccine candidate developed with pharmaceutical company Johnson & Johnson.
The early results — which were published in medRxiv Friday, but have yet to be peer-reviewed — indicate that a single dose of the Johnson & Johnson vaccine safely elicits antibody responses in nearly all participants across all age groups.
HMS professor Dan H. Barouch ’93, who serves as Director of Beth Israel’s Center for Virology and Vaccine Research, led the design effort for the vaccine. It uses a deactivated common cold virus as a viral vector to deliver coronavirus spike proteins to host cells, stimulating the body to elicit an immune response.
Barouch said the data shows the vaccine is “generally well tolerated,” noting that just a single shot provoked an immune response in “the vast majority” of study participants.
The “single shot” characteristic of the vaccine is a distinguishing feature of its design, according to Barouch.
“A single shot vaccine, if it proves to be safe and effective, would have substantial practical and logistic benefits in terms of mass immunization campaigns and global pandemic control,” he said.
Moreover, the vaccine does not require sub-zero freezing for stability and can remain stable at refrigerated temperatures for up to three months. Other vaccine candidates in late stage clinical trials must be frozen, requiring dry ice for distribution.
Still, despite hopeful preliminary findings, the research team will not know if their vaccine effectively defends against the coronavirus until the completion of phase three clinical trials, which will be led by Johnson & Johnson and the National Institutes of Health’s COVID-19 Prevention Trials Networks. The trials will enroll 60,000 participants from around the world.
“We don’t know yet that these antibody responses will actually protect anyone from getting COVID-19, or developing severe disease,” Kathryn Stephenson, Director of the Center for Virology and Vaccine Research Clinical Trials Unit at BIDMC, wrote in an email. “That’s why it’s so important that we do these phase 3 trials.”
Barouch said his team is “tremendously excited” about pushing ahead into the late stage clinical trials.
“The pre-clinical studies and the early phase clinical trials look promising and we look forward to the results of the definitive, pivotal phase three trial of this vaccine,” he said.
—Staff writer Alex M. Koller can be reached at firstname.lastname@example.org.