- Single booster dose of 50 µg of mRNA-1273 or mRNA-1273.351 increased neutralizing titers against SARS-CoV-2 and two variants of concern (B.1.351, P.1) in previously vaccinated clinical trial participants
- Booster dose of mRNA-1273.351, a strain-matched candidate, achieved higher titers against B.1.351 than a booster dose of mRNA-1273
- mRNA-1273.351 and mRNA-1273 booster doses were generally well tolerated
- Evaluation of a multivalent vaccine booster candidate, mRNA-1273.211, is ongoing; data expected shortly
Moderna, Inc. announced initial data from its Phase 2 study showing that a single 50 µg dose of mRNA-1273 or mRNA-1273.351 given as a booster to previously vaccinated individuals increased neutralizing antibody titer responses against SARS-CoV-2 and two variants of concern, B.1.351 (first identified in South Africa) and P.1 (first identified in Brazil). A booster dose of mRNA-1273.351, the Company’s strain-matched booster, achieved higher neutralizing antibody titers against the B.1.351 variant of concern than a booster dose of mRNA-1273. A manuscript describing these preliminary results has been submitted as a preprint to bioRxiv and will be submitted for peer-reviewed publication upon completion of the multivalent mRNA-1273.211 booster arm.
“As we seek to defeat the ongoing pandemic, we remain committed to being proactive as the virus evolves. We are encouraged by these new data, which reinforce our confidence that our booster strategy should be protective against these newly detected variants. The strong and rapid boost in titers to levels above primary vaccination also clearly demonstrates the ability of mRNA-1273 to induce immune memory,” said Stéphane Bancel, Chief Executive Officer of Moderna. “Our mRNA platform allows for rapid design of vaccine candidates that incorporate key virus mutations, potentially allowing for faster development of future alternative variant-matched vaccines should they be needed. We look forward to sharing data on our multivalent booster candidate, mRNA-1273.211, which combines mRNA-1273 and mRNA-1273.351 in a single vaccine, when available. We will continue to make as many updates to our COVID-19 vaccine as necessary to control the pandemic.”