Covid-19 vaccine from US firm Moderna 94.5% effective, clinical trials show 1 year ago

Covid-19 vaccine from US firm Moderna 94.5% effective, clinical trials show

A further promising development in the fight against Covid-19.

US pharmaceutical company Moderna has announced that its Covid-19 vaccine was found to be 94.5% effective in analysis of Phase 3 clinical trials.


The news comes a week to the day after Pfizer announced that a Covid-19 vaccine it had manufactured with BioNTech was over 90% effective, a day described as “a great day for science and humanity” by Pfizer Chariman, Dr. Albert Bourla.

In a statement on Monday, Moderna said that 30,000 participants in the US were enrolled as part of the Phase 3 COVE study, which was based on “the analysis of Covid-19 cases confirmed and adjudicated starting two weeks following the second dose of vaccine”.

The first interim analysis, Moderna said, was based on 95 cases, including 15 older adults (65+) and 20 cases from people identifying as being from diverse communities.

90 cases of Covid-19 were observed in the placebo group as opposed to five cases observed in the group treated with Moderna’s vaccine candidate, mRNA-1273, leading to a point estimate of vaccine efficacy of 94.5%.

More severe cases of Covid-19 were also examined, including 11 severe cases in the first interim analysis.

The results showed that all 11 cases occurred in the placebo group and none in the group treated with the Moderna vaccine candidate.

The Data Safety Monitoring Board found no significant safety concerns and a review found that the vaccine was generally well tolerated.


Side effects, including injection site pain, fatigue, myalgia, arthralgia and headache, were found to be “mild or moderate in severity” and were “generally short lived”.

Significantly, Moderna also announced the vaccine is expected to remain stable at standard refrigerator temperatures of 2° to 8°C for 30 days, up from a previous estimate of seven days.

Moderna said that the estimate for vaccine efficacy of 94.5% may change and could drop as further results from the clinical trial are revealed.

The company plans to submit data from the full study to a peer-reviewed publication and to submit it for an Emergency Use Authorisation (EUA) with the US Food and Drug Administration (FDA) in the coming weeks.

Moderna said it expects to have approximately 20 million doses of the vaccine ready to ship in the US by the end of 2020 and is on track to manufacture 500 million to 1 billion doses of it globally in 2021.


“This is a pivotal moment in the development of our Covid-19 vaccine candidate,” said Stéphane Bancel, CEO of Moderna.

“Since early January, we have chased this virus with the intent to protect as many people around the world as possible. All along, we have known that each day matters.

“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.”