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The recently approved COVID-19 vaccine, developed by Moderna and the National Institute of Allergy and Infectious Diseases (NIAID), was 94.1% effective in preventing symptomatic COVID-19, according to the results of phase 3 studies based on December 30 were published in The New England Journal of Medicine.
There were no cases of severe COVID-19 among participants who received the vaccine, known as mRNA-1273, and there were no safety concerns.
The U.S. Food and Drug Administration issued an emergency use license on December 18 for the vaccine, a lipid nanoparticle encapsulated mRNA vaccine that expresses the prefusion-stabilized peak glycoprotein.
The trial began in July, and 30,420 adults were enrolled in the United States. Volunteers were randomly assigned in a 1: 1 ratio to receive either two doses of the vaccine or two injections of saline placebo 28 days apart. The mean age of the participants was 51 years.
A total of 196 cases of symptomatic COVID-19 occurred at least 14 days after the participants received their second injection – 185 cases in the placebo group and 11 in the vaccine group.
In a secondary analysis that included cases that occurred at least 14 days after the first injection, vaccine efficacy was 95.2%, report study author Lindsey R. Baden, MD, of Brigham and Women’s Hospital, Boston, Massachusetts, and colleagues.
About half 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. Most side effects disappeared within 20 days.
Future studies
Future studies will assess the effect of the vaccine on infectivity.
Both the Moderna vaccine and the Pfizer-BioNTech vaccine “begin to protect recipients approximately 10 days after the first dose, with maximum protection after the second dose,” said Barton F. Haynes, MD, in an accompanying editorial.
That both “have nearly identical 94% to 95% vaccine efficacy – and that both vaccines were developed and tested in less than a year – are extraordinary scientific and medical triumphs,” said Haynes, director of the Duke Human Vaccine Institute, Durham, North Carolina. .
“mRNA technology has the potential to revolutionize vaccine design for future virus outbreaks,” he said.
Ongoing safety monitoring and analysis of virus escape from protective immune responses will be important, Haynes added.
Subgroup analyzes by age, gender, race / ethnicity and risk of severe COVID-19 showed “maintenance of efficacy across the board”, tweeted Medscape Editor-in-Chief Eric Topol, MD, Leader of the Scripps Translational Science Institute in La Jolla, California.
Subgroup analysis, maintenance of efficacy across the board pic.twitter.com/SbxeQMTYRz
— Eric Topol (@EricTopol) December 30, 2020
Topol emphasized the absence of severe COVID-19 among participants who received the vaccine. All 30 study participants who developed severe COVID-19 were in the placebo group. One death among those participants was attributed to COVID-19.
The study was supported by the Biomedical Advanced Research and Development Authority and the NIAID. Baden is deputy editor at the The New England Journal of Medicine and received NIH fellowships during the study. Baden is partnering with federal agencies, companies and foundations on clinical trials of HIV and COVID-19 vaccines. Some of the study co-authors are Moderna employees or have affiliations with pharmaceutical companies or disclosed grants from foundations and federal agencies. Haynes owned Moderna stock at one point in the past year, has received grants from the NIH outside of the work filed, and has pending patents related to the development of COVID-19 vaccines. He worked with Baden on research projects on HIV vaccines.
N Engl J Med. Published online December 30, 2020. Full text
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