Moderna has announced new clinical data on its Omicron BA.1-targeting bivalent vaccine, mRNA-1273.214, which demonstrated a ‘superior neutralising antibody response’ 90 days after administration as a fourth booster compared to Spikevax prototype booster, mRNA-1273.
The superior response was seen in all participants, regardless of prior infection, with higher antibody titres sustained for at least three months.
In addition, mRNA-1273.214 demonstrated significantly higher neutralising antibody responses against Omicron BA.4/BA.5 compared to mRNA-1273 28 days after administration, as previously reported by the company.
Potent responses were also seen against Omicron BA.2.75 28 days after administration, suggesting that the bivalent booster elicits broad cross-neutralisation against Omicron variants.
“Our bivalent boosters continue to demonstrate a strong, enduring response to COVID-19 variants of concern,” said Stéphane Bancel, chief executive officer of Moderna.
He continued: “Clinical trial data now indicates that the superior immune response produced by our bivalent booster has durability for at least three months. As COVID-19 remains a global threat and a leading cause of death globally, this is an encouraging development, showing that a bivalent booster dose will offer important protection leading into the winter months.”
In terms of safety, observed side effects of mRNA-1273.214 were similar or less severe than those of either a second or third dose of the original vaccine and no new safety concerns were identified in the three-month follow-up, the company reported.
In July 2022, Moderna announced the advancement of two bivalent candidates for autumn, based on different population health security strategies in different countries. mRNA-1273.214 contains the BA.1 Omicron strain, while mRNA-1273.222 contains the BA.4/BA.5 Omicron strain. Both bivalent candidates contain 25µg of mRNA-1273 and 25µg of an Omicron subvariant.
The company expects interim safety and immunogenicity results of its Omicron BA.4/BA.5-targeting bivalent vaccine to become available later this year.
Most recently, the company received Emergency Use Authorisation (EUA) from the US Food and Drug Administration (FDA) this month for a 25μg booster dose of mRNA-1273.222 in children and adolescents aged six to 17 years.
This builds on the EUA the company received from the FDA in August for use of a 50μg dose of mRNA-1273.222 in adults 18 years and over.
The Omicron-adapted booster has also received authorisations in the UK, Europe, Australia, Canada, Japan, South Korea, Switzerland, Singapore and Taiwan to date.