News release
Wednesday December 30, 2020
Phase 3 clinical trial data confirms the vaccine’s effectiveness.
What
The study vaccine known as mRNA-1273 was 94.1% effective in preventing symptomatic coronavirus disease 2019 (COVID-19), according to preliminary results from a phase 3 clinical trial reported in the New England Journal of Medicine. The vaccine also showed efficacy in preventing severe COVID-19. Researchers have not identified any safety concerns and no evidence of vaccination-associated enhanced respiratory disease (VAERD).
The vaccine was co-developed by Moderna, Inc., a biotechnology company based in Cambridge, Massachusetts, and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Moderna and NIAID previously shared the initial results of the COVE study. On December 18, 2020, the FDA issued an emergency use authorization, allowing Moderna to make the vaccine available for the prevention of COVID-19 in adults in the United States.
The trial was led by lead investigators Lindsey R. Baden, MD of Brigham and Women’s Hospital in Boston, Hana M. El-Sahly, MD of Baylor College of Medicine in Houston, and Brandon Essink, MD, of Meridian Clinical Research. The trial was conducted under the US government’s Operation Warp Speed program and was supported by NIAID and the Biomedical Advanced Research and Development Authority (BARDA) of the US Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response .
The trial began on July 27, 2020 and 30,420 adult volunteers were enrolled at clinical trial centers in the United States. Volunteers were randomly assigned 1: 1 to receive either two 100 microgram (mcg) doses of study vaccine or two injections of saline 28 days apart. The average age of volunteers is 51 years. About 47% are female, 25% are 65 or older, and 17% are under 65 with medical conditions that put them at higher risk for severe COVID-19. About 79% of the participants are White, 10% are Black or African American, 5% are Asian, 0.8% are Amerindian or Alaska Native, 0.2% are Native Hawaiian or other Pacific Islander, 2% is multiracial and 21% (of any race) are Hispanic or Latino.
From the start of the study through November 25, 2020, researchers recorded 196 cases of symptomatic COVID-19 in participants at least 14 days after they received their second injection. One hundred eighty-five cases (of which 30 classified as severe COVID-19) occurred in the placebo group and 11 cases (of which 0 classified as severe COVID-19) occurred in the group receiving mRNA-1273. The incidence of symptomatic COVID-19 was 94.1% lower in the participants who received mRNA-1273 compared to those who received placebo.
Researchers observed 236 cases of symptomatic COVID-19 among participants at least 14 days after they received their first injection, with 225 cases in the placebo group and 11 cases in the mRNA-1273 group. The vaccine efficacy was 95.2% for this secondary analysis.
According to the authors there were no safety concerns with vaccination. Local reactions to the vaccine were generally mild. About 50% of the participants who received mRNA-1273 experienced moderate to severe side effects – such as fatigue, muscle pain, joint pain, and headache – after the second dose, which resolved within two days in most volunteers.
Researchers also observed no evidence of VAERD among those who received mRNA-1273. This rare complication was seen in subjects vaccinated with a fully inactivated respiratory syncytial virus (RSV) vaccine in the 1960s, before there was a capacity to define protein structures and measure immune responses with precision. VAERD can occur when a vaccine elicits an immune response that is not strong enough to protect against infection.
Although mRNA-1273 is highly effective in preventing symptomatic COVID-19, sufficient data is not yet available to draw any conclusions as to whether the vaccine can affect SARS-CoV-2 transmission. Preliminary research data suggests that there may be some degree of prevention of asymptomatic infection after a single dose. Additional analyzes are underway of the incidence of asymptomatic infection and virus shedding after infection to understand the impact of the vaccine on the infectious agent.
The authors concluded by discussing the unprecedented efficiency of the development of the vaccine candidate, noting, “This process shows what is possible in the context of motivated collaboration between key sectors of society, including academia,” government, industry, regulators and the wider community. “
Article
LR Baden, et al. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. The New England Journal of Medicine. DOI: 10.1056 / NEJMoa2035389.
Who
NIAID Director Anthony S. Fauci, MD is available to comment on this study. John R. Mascola, MD, director of NIAID’s Vaccine Research Center, is also available for comment.
Contact
To schedule interviews, contact the NIAID News & Science Writing Branch, (301) 402-1663, [email protected].
NIAID conducts and supports research – at NIH, in the United States and worldwide – to study the causes of infectious and immune-mediated diseases and to develop better means to prevent, diagnose and treat these diseases. News releases, fact sheets and other NIAID-related material are available on the NIAID website.
About the National Institutes of Health (NIH):
NIH, the national medical research agency, includes 27 institutes and centers and is part of the United States Department of Health and Human Services. NIH is the premier federal agency that conducts and supports basic, clinical, and translational medical research, investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
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