High efficacy, long shelf life for Moderna's COVID-19 vaccine

Interim analysis of Moderna’s Phase 3 study of mRNA-1273, an mRNA vaccine candidate for COVID-19, finds that the vaccine has an efficacy of 94.5% — even higher than the reported 90% efficacy of Pfizer and BioNTech’s candidate and Russia’s 92%.

The so-called ‘COVE’ study enrolled more than 30,000 participants in the US, including more than 7000 Americans over the age of 65, more than 5000 with high-risk chronic diseases that put them at increased risk of severe COVID-19 and more than 11,000 from communities of colour. It is being conducted in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), and the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response at the US Department of Health & Human Services.

The primary endpoint of the Phase 3 study — ie, the prevention of symptomatic COVID-19 disease — is based on the analysis of COVID-19 cases confirmed and adjudicated starting two weeks following the second dose of vaccine. This first interim analysis was based on 95 cases, of which 90 cases of COVID-19 were observed in the placebo group versus five cases observed in the mRNA-1273 group, resulting in a point estimate of vaccine efficacy of 94.5%. A secondary endpoint analysed severe cases of COVID-19 and included 11 severe cases in this first interim analysis, all of which occurred in the placebo group. The interim analysis also included a concurrent review of the available Phase 3 COVE study safety data by an NIH-appointed Data Safety Monitoring Board (DSMB), which did not report any significant safety concerns.

The company has additionally announced new data showing that mRNA-1273 remains stable at -20°C, equal to most home or medical freezer temperatures, for up to six months. This should allow for an easier and more established method of distribution and storage than deep freezing, with most pharmaceutical distribution companies having the capability to store and ship products at -20°C worldwide.

After thawing, to facilitate storage at points of administration, Moderna expects that mRNA-1273 will remain stable at standard refrigerated conditions of 2–8°C for up to 30 days within the six-month shelf life. The stability at refrigerated conditions allows for storage at most pharmacies, hospitals or physicians’ offices.

Once the vaccine is removed from the refrigerator for administration, it can be kept at room-temperature conditions for up to 12 hours. Furthermore, the vaccine does not require onsite dilution or special handling, which facilitates vaccination across a range of settings including pharmacies and physicians’ offices.

Based on the interim safety, efficacy and stability data, Moderna intends to submit for an Emergency Use Authorization (EUA) with the US FDA in the coming weeks and anticipates having the EUA informed by the vaccine’s final safety and efficacy data (with a median duration of at least two months), which will be submitted to a peer-reviewed publication. The company also plans to submit applications for authorisations to global regulatory agencies.

In the event that it receives an EUA and similar global authorisations, Moderna expects to have approximately 20 million doses of mRNA-1273 ready to ship in the US by the end of 2020. The company also remains on track to manufacture 500 million to 1 billion doses globally in 2021, and while Australia does not have any direct agreements with Moderna, the vaccine could make its way down under thanks to our membership of the COVAX facility — a coalition of 188 countries allowing members to purchase COVID-19 vaccines if and when they become available.

Image credit: ©ZSOLNAI GERGELY/Dollar Photo Club

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