A phase 3 trial evaluating the vaccine candidate mRNA-1273 against coronavirus disease 2019 (COVID-19) met its primary efficacy end point in the first interim analysis, according to developer Moderna.

The randomized, placebo-controlled COVE study is investigating the efficacy and safety of mRNA-1273 at the 100mcg dose (given intramuscularly in a 2-dose series, approximately 28 days apart) in more than 30,000 adults aged 18 years and older. The primary efficacy end point of the trial is the prevention of symptomatic COVID-19 disease based on the analysis of cases confirmed and adjudicated starting 2 weeks after the second dose.

Findings reported by an independent National Institutes of Health (NIH)-appointed data safety monitoring board (DSMB) showed that the vaccine was 94.5% effective (P <.0001) based on 95 confirmed cases, of which 90 occurred in the placebo group and 5 occurred in the mRNA-1273 group. The data also included 11 severe cases, all of which were among participants in the placebo group.

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According to the DSMB, no significant safety concerns were noted in the interim analysis and preliminary data suggest a consistent safety and efficacy profile across the evaluated subgroups. The COVE trial includes more than 7000 US adults over 65 years old, 5000 participants under 65 living with high-risk chronic diseases (ie, diabetes, severe obesity, significant cardiac disease, chronic lung disease), 6000 participants who identify as Hispanic or Latinx, and more than 3000 participants who identify as Black or African American.

The final estimates of vaccine efficacy will be reported when the trial reaches 151 cases. Moderna intends to submit for an Emergency Use Authorization with the Food and Drug Administration in the coming weeks.

The Company also announced new stability data showing that the vaccine candidate remains stable at 2° to 8°C (36° to 46°F) for up to 30 days, in addition to being stable at -20° C (-4°F) for up to 6 months and at room temperature for up to 12 hours.

“The ability to store our vaccine for up to 6 months at -20° C including up to 30 days at normal refrigerator conditions after thawing is an important development and would enable simpler distribution and more flexibility to facilitate wider-scale vaccination in the United States and other parts of the world,” said Juan Andres, Chief Technical Operations and Quality Officer at Moderna. “We are pleased to submit these extended stability conditions for mRNA-1273 to regulators for approval.”

For more information visit modernatx.com.


  1. Moderna’s COVID-19 vaccine candidate meets its primary efficacy endpoint in the first interim analysis of the phase 3 COVE study. [press release]. Cambridge, MA; November 16, 2020.
  2. Moderna announces longer shelf life for its COVID-19 vaccine candidate at refrigerated temperatures. [press release]. Cambridge, MA; November 16, 2020.

This article originally appeared on MPR