An investigational vaccine tested at Emory is 94.5 percent effective at preventing COVID-19, according to early results from a large-scale clinical trial.

The vaccine, mRNA-1273, was co-developed by researchers at the National Institute of Allergy and Infectious Diseases (NIAID) and biotech company Moderna, Inc., of Cambridge, Mass.

Emory enrolled about 700 people as part of the Phase 3 trial, also known as the COVE study. 

The mRNA-1273 vaccine is being tested at three Emory clinics under the direction of a  trio principal investigators.

• Hope Clinic: Nadine Rouphael, MD, professor of medicine (infectious diseases) at Emory University School of Medicine, interim director at the Hope Clinic
• Emory Children's Center — Vaccine Research Clinic: Evan Anderson, MD, professor of medicine and pediatrics at Emory University School of Medicine, physician at Children’s Healthcare of Atlanta.
• Ponce De Leon Center/Grady Clinic: Colleen Kelley, MD, MPH, associate professor of medicine (infectious diseases) at Emory University School of Medicine.

The study enrolled more than 30,000 participants in the United States. They were given two shots 28 days apart. Half of the participants were given the vaccine and half a placebo.

In an analysis released on Monday by Moderna, 95 participants contracted COVID. Ninety of those cases were in a placebo group and five in the group that received mRNA-1273. Eleven of the COVID infections were categorized as severe and all of them were in the placebo group.

Emory was the second site in the nation to enroll volunteers in the initial Phase 1 study of the vaccine, which established the dose and looked at whether the vaccine was safe. Researchers said the results showed the vaccine was generally well tolerated and stimulated a robust immune response.

Recently, Emory began enrolling participants in a large trial of another vaccine candidate developed by the Janssen Pharmaceutical Companies of Johnson & Johnson. It is the first Phase 3 clinical trial to assess if a single dose vaccine can protect people against COVID-19.

The COVE study was conducted by Emory’s Vaccine and Treatment Evaluation Unit (VTEU), which is part of NIAID’s Infectious Diseases Clinical Research Consortium (IDCRC) and the COVID-19 Prevention Network (CoVPN) supporting this trial. Emory has been a VTEU site since 2007. The consortium is co-led by co-principal investigators David S. Stephens of Emory University School of Medicine, and Kathleen Neuzil of the University of Maryland School of Medicine. Stephens is professor and chair of Emory’s Department of Medicine and vice president for research of the Woodruff Health Sciences Center.