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The recently authorized 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 the phase 3 trial published on 30 December in The new English medical journal.
No cases of severe COVID-19 occurred among participants who received the vaccine, known as mRNA-1273, and there were no safety concerns.
On December 18, the Food and Drug Administration issued an emergency use authorization for the vaccine, a mRNA vaccine encapsulated in lipid nanoparticles that expresses the pre-fused stabilized peak glycoprotein.
The trial began in July and involved 30,420 adults in the United States. Volunteers were randomly assigned a 1: 1 ratio to receive two doses of the vaccine or two injections of saline placebo 28 days apart. The average age of the participants was 51 years.
In all, 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, the vaccine’s effectiveness was 95.2%, reported study author Lindsey R. Baden, MD, 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 adverse events were resolved in 20 days.
Future Studies
Future studies will assess the effect of the vaccine on infectivity.
Both the Modern 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.
The fact that both have “nearly identical 94% to 95% vaccine efficacies – 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 radically change the design of the vaccine for future viral outbreaks,” he said.
Continuous security monitoring and analysis of the virus escape from protective immune responses will be important, added Haynes.
Subgroup analyzes by age, sex, race / ethnicity and risk of severe COVID-19 showed “maintenance of effectiveness in all areas”, 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 highlighted the absence of serious 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 these participants was attributed to COVID-19.
The study was supported by the Advanced Biomedical Research and Development Authority and NIAID. Baden is deputy editor of The new English medical journal and received NIH grants during the study. Baden collaborates with federal agencies, companies and foundations in clinical trials of HIV and COVID-19 vaccines. Some co-authors of the study are employees of Moderna or disclosed links with pharmaceutical companies or donations from federal foundations and agencies. Haynes owned shares of Moderna at one point during the past year, received donations from NIH outside of the submitted work and has pending patents related to the development of the COVID-19 vaccine. He has collaborated with Baden on HIV vaccine research projects.
N Engl J Med. Published online December 30, 2020. Full text
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