Moderna Inc. (MRNA) said initial data from its ongoing phase 2 study showed that booster shots of its COVID-19 vaccine is effective against strains of the coronavirus that emerged from Brazil and South Africa. The company is also evaluating a multivalent vaccine booster candidate, mRNA-1273.211, and expects to share its data shortly.
The biotechnology company said initial data from its phase 2 study showed that a single 50 µg dose of mRNA-1273 or mRNA-1273.351 given as a booster to previously vaccinated clinical trial participants increased neutralizing antibody titer responses against SARS-CoV-2 and two variants of concern, the B.1.351 (first identified in the Republic of South Africa) and the P.1 (first identified in Brazil).
A booster dose of mRNA-1273.351 achieved higher neutralizing antibody titers against the South Africa variant of concern than a booster dose of mRNA-1273. The safety and tolerability profiles following third dose booster injections of 50 µg of mRNA-1273 or mRNA-1273.351 were generally comparable to those observed after the second dose of mRNA-1273 in the previously reported Phase 2 and Phase 3 studies. The majority of adverse events were mild or moderate in severity. In the ongoing phase 2 study, three strategies for boosting neutralizing titers in previously vaccinated participants are being evaluated: mRNA-1273.351, a booster candidate based on the South African variant; mRNA-1273.211, a multivalent booster candidate which combines a 50-50 mix of mRNA-1273, Moderna's authorized vaccine against ancestral strains and mRNA-1273.351 in a single vaccine, and a 50 µg booster dose of mRNA-1273.
The update includes preliminary data two weeks following administration of a booster dose of mRNA-1273 or mRNA-1273.351. Evaluation of additional samples collected at later timepoints after the booster, the company's multivalent vaccine candidate, mRNA-1273.211, and a lower dose of mRNA-1273.351 are ongoing and data is expected shortly.
Moderna COVID-19 Vaccine is authorized for use under an Emergency Use Authorization for active immunization to prevent COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals 18 years of age and older.
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