Moderna Begins Phase 3 Coronavirus Vaccine Trials


Moderna, Inc., a Cambridge-based biotechnology company, has begun the Phase 3 clinical trial of its coronavirus vaccine candidate, the company announced Monday.

The trial will test the safety and efficacy of the vaccine in preventing symptomatic Covid-19 disease after two doses and is expected to enroll 30,000 participants at nearly 100 research sites.

Moderna is conducting the study in collaboration with the National Institute of Allergy and Infectious Diseases — part of the National Institutes of Health — and the Biomedical Advanced Research and Development Authority of the U.S. Department of Health and Human Services.

In late March, the National Institutes of Health announced it would begin Phase 1 study, and Moderna received FDA approval to proceed with Phase 2 in early May.


In a press release Monday, Moderna CEO Stéphane Bancel praised the work of those involved in the vaccine’s development.

“We are grateful to the efforts of so many inside and outside the company to get us to this important milestone,” Bancel said. “We look forward to this trial demonstrating the potential of our vaccine to prevent COVID-19, so that we can defeat this pandemic.”

The vaccine, known as mRNA-1273, was created using the genetic sequence of the coronavirus, which is available in a public database. Scientists at Moderna and the NIH identified the sequence for a protein on the surface of the virus, known as the spike protein, as a candidate for a vaccine, according to Moderna’s website.

The instructions for making the spike protein were then encoded into mRNA, which could be administered to patients as a vaccine. The vaccine then instructs the body’s cells to express the spike protein and elicit an immune response.

“What makes this approach different is that you don’t need to make the virus itself to make a vaccine — a time consuming and intensive process,” a video on Moderna’s website states. “Instead you use the information from the virus and administer the information directly to the patient.”

“Essentially, the patient makes their own vaccine,” the video adds.

The video credits this unique process for Moderna and NIH’s ability “to go from sequence to a vaccine ready for human testing in record time — just 42 days.”

Volunteer trial participants for the Phase 3 study will receive two injections approximately 28 days apart. Half of the participants will receive injections of the vaccine, while the other half will be given shots of a saline placebo. Investigators and participants will not know who is receiving the vaccine and who is not.

Scientists will then examine blood samples from the participants and monitor immune responses to the coronavirus. Participants will also be tested for Covid-19 periodically, and study investigators will review trial safety data regularly.

In addition to preventing symptomatic SARS-Cov-2 infection, other objectives for study in the trial include testing whether the vaccine can prevent the disease without symptoms and whether just one dose is enough to prevent symptomatic Covid-19.

A press release on Moderna’s website also states the company is “on track” to be able to deliver approximately 500 million doses per year — possibly 1 billion doses per year — beginning in 2021, due to their manufacturing capabilities and collaborations with biotechnology company Lonza, Ltd. and pharmaceutical provider Catalent, Inc.

NIH Director Francis S. Collins said in a press release having a vaccine available by the end of 2020 remains their objective.

“Having a safe and effective vaccine distributed by the end of 2020 is a stretch goal, but it’s the right goal for the American people,” he said.

—Staff writer Taylor C. Peterman can be reached at Follow her on Twitter @taylorcpeterman.