In preliminary showings, a third dose of Moderna Inc’s COVID-19 vaccine increased antibody levels against the Omicron variant currently sweeping the world, painting the company’s strategy forward even as a years-long pandemic continues to evolve.
The report followed news that omicron, which originated in South Africa, now accounts for 73 percent of new COVID-19 cases sweeping the U.S. However, Moderna’s data provided some reassurance, noting that a 50 µg dose of its mRNA-1273 vaccine formulation provided a 37-fold increase in neutralizing antibodies. That is its currently authorized booster — a dose half the strength of those used for primary immunization regimens.
Notably, a 100 µg dose boosted antibody levels 83-fold.
“The dramatic increase in COVID-19 cases from the Omicron variant is concerning to all. However, these data showing that the currently authorized Moderna COVID-19 booster can boost neutralizing antibody levels 37-fold higher than pre-boost levels are reassuring,” Stéphane Bancel, CEO of Moderna, said in a statement. “To respond to this highly transmissible variant, Moderna will continue to rapidly advance an Omicron-specific booster candidate into clinical testing in case it becomes necessary in the future.”
The data was pulled from 20 booster recipients for each level of dosage, multivalent candidate mRNA-1273.211 at the 50 µg and 100 µg dose levels, and multivalent candidate mRNA-1273.213 at the 100 µg dose level. Antibody levels were determined through an assay conducted at labs run by the National Institute of Allergy and Infectious Diseases’ (NIAID) Vaccine Research Center and Duke University Medical Center.
The previously-noted 37-fold increase was determined at 29 days post-booster. How long it will last, however, remains undetermined.
Going forward, the company intends to continue advancing booster candidates for emerging variants of concern such as delta and omicron, as well as evaluating its original mRNA-1273 vaccine and multivalent candidates. Booster candidates are undergoing Phase 2/3 studies of approximately 300-600 participants each to determine their potential. However, given the new data and the rapid spread of omicron, Moderna announced it will focus its near-term efforts on the mRNA-1273 booster.