The Moderna mRNA-1273 vaccine, in development to prevent COVID-19, yielded 94.5% efficacy in early results and is generally well tolerated, the company announced early Monday. The product can be stored at refrigeration temperatures common to many physician offices, pharmacies, and hospitals.
The first interim results of the phase 3 COVE trial included 95 participants with confirmed COVID-19. An independent data safety monitoring board, which was appointed by the National Institutes of Health, informed Moderna that 90 of the patients who were positive for COVID-19 were in a placebo group and that 5 patients were in the mRNA-1273 vaccine group, resulting in a vaccine efficacy of 94.5% ( P < .0001).
Interim data included 11 patients with severe COVID-19, all of whom were in the placebo group.
“This positive interim analysis from our phase 3 study has given us the first clinical validation that our vaccine can prevent COVID-19 disease, including severe disease,” said Stéphane Bancel, CEO of Moderna, said in a statement.
The vaccine met its primary study endpoint, which was based on adjudicated data that were collected starting 2 weeks after the second dose of mRNA-1273. The interim study population included people who could be at higher risk for COVID-19, including 15 adults aged 65 years and older and 20 participants from diverse communities.
The DSMB also reviewed safety data for the COVE study interim results. The vaccine was generally safe and well tolerated, as determined on the basis of solicited adverse events. Most adverse events were mild to moderate and were generally short-lived, according to a company news release.
Injection-site pain was reported in 2.7% of participants after the first dose. After the second dose, 9.7% of participants reported fatigue, 8.9% reported myalgia, 5.2% reported arthralgia, 4.5% reported headache, 4.1% reported pain, and 2.0% reported erythema or redness at the injection site.
Moderna plans to request emergency-use authorization (EUA) from the Food and Drug Administration in the coming weeks. The company expects that the EUA will be based on more data from the COVE study, including a final analysis of 151 patients with a median follow-up of more than 2 months. Moderna also plans to seek authorizations from global regulatory agencies.
The company expects to have approximately 20 million doses of mRNA-1273 ready to ship in the United States by the end of the year. In addition, the company says it remains on track to manufacture between 500 million and 1 billion doses globally in 2021.
Moderna is developing distribution plans in conjunction with the Centers for Disease Control and Prevention, the federal government’s Operation Warp Speed, and McKesson, a COVID-19 vaccine distributor contracted by the U.S. government.
The mRNA-1273 vaccine can be shipped and stored for up to 6 months at –20° C (about –4° F), a temperature maintained in most home or medical freezers, according to Moderna. The company expects that, after the product thaws, it will remain stable at standard refrigerator temperatures of 2°-8° C (36°-46° F) for up to 30 days within the 6-month shelf life.