The vaccine, mRNA-1273.214, has been granted conditional authorization in individuals aged 18+ as a booster dose by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), Moderna announced yesterday.
In each dose of the booster vaccine, half of the vaccine (25 micrograms) targets the original virus strain from 2020 and the other half (25 micrograms) targets Omicron.
Phase 2/3 trial
The decision from the MHRA was based on clinical trial data from a phase 2/3 trial, in which mRNA-1273.214 met all primary endpoints, including superior neutralizing antibody response against Omicron (BA.1) when compared to a 50 µg booster dose of mRNA-1273 in baseline seronegative participants.
A booster dose of mRNA-1273.214 increased neutralizing geometric mean titers (GMT) against Omicron approximately 8-fold above baseline levels.
In addition, mRNA-1273.214 elicited ‘potent neutralizing antibody’ responses against the Omicron subvariants BA.4 and BA.5 compared to the currently authorized booster (mRNA-1273) regardless of prior infection status or age.
"We are delighted with the MHRA's authorization of Spikevax Bivalent Original/Omicron, our next-generation COVID-19 vaccine. This represents the first authorization of an Omicron-containing bivalent vaccine, further highlighting the dedication and leadership of the UK public health authorities in helping to end the COVID-19 pandemic," said Stéphane Bancel, CEO of Moderna.
"mRNA-1273.214 has consistently shown superior breadth of immune response over mRNA-1273 in clinical trials. This bivalent vaccine has an important role to play in protecting people in the UK from COVID-19 as we enter the winter months."
'Sharpened tool' against COVID-19
The MHRA – which first authorized the original vaccine in January 2021 and has since been using it as both a primary vaccine and booster option - says the bivalent vaccine will provide an additional tool in the fight against COVID-19.
“The first generation of COVID-19 vaccines being used in the UK continue to provide important protection against the disease and save lives. What this bivalent vaccine gives us is a sharpened tool in our armoury to help protect us against this disease as the virus continues to evolve,” said Dr June Raine, MHRA chief executive.
“The virus, SARS-CoV-2, is continually evolving in order to evade the immunity provided by vaccines. This novel bivalent vaccine represents the next step in the development of vaccines to combat the virus, with its ability to lead to a broader immune response than the original vaccine,” added Professor Sir Munir Pirmohamed, Chair of the Commission on Human Medicines.
The UK’s Joint Committee on Vaccination and Immunisation (JCVI) will now advise on how this vaccine will be rolled out in the UK.
Meanwhile, Moderna has completed regulatory submissions for mRNA-1273.214 in Australia, Canada, and the EU and expects further authorization decisions to follow in the coming weeks.
The bivalent booster is likely to represent an important part of vaccination strategies as northern hemisphere countries move towards winter.
In the EU, for example, Moderna and the European Commission have amended their supply agreement: which will now convert contractually agreed doses of Moderna's original COVID-19 vaccine (Spikevax, mRNA-1273) to Omicron-containing bivalent vaccines for supply in 2022, pending regulatory approval. The EC has also added an additional 15 million doses of Omicron-containing vaccine booster shots to its order with Moderna.
Under this amendment, announced last week, Spikevax mRNA-1273 doses scheduled to be delivered in July and August will now be deferred to later in 2022, with all doses of mRNA-1273 converted to Omicron-containing bivalent vaccines.
Moderna is advancing two bivalent candidates. The mRNA-1273.214 bivalent booster - as authorized by the UK - is based on the Omicron subvariant BA.1. The second bivalent booster candidate, mRNA 1273.222, is based on the BA.4/5 strain.