The study was conducted at laboratories established by the National Institute of Allergy and Infectious Diseases’ (NIAID) Vaccine Research Center at Duke University Medical Center. Sera were collected from 20 booster recipients each of mRNA-1273 at the 50mcg and 100mcg dose levels, multivalent candidate mRNA-1273.211 at the 50mcg and 100mcg dose levels, and multivalent candidate mRNA-1273.213 at the 100mcg dose level.

At day 29 post boost, results showed an approximately 37-fold increase in neutralizing antibody levels against Omicron with the 50mcg booster dose and an approximately 83-fold increase with the 100mcg booster dose, when compared with preboost levels. Similarly high levels of Omicron specific neutralizing antibodies were observed following receipt of the multivalent vaccine candidates.

“These data showing that the currently authorized Moderna COVID-19 booster can boost neutralizing antibody levels 37-fold higher than preboost levels are reassuring,” said Stéphane Bancel, CEO of Moderna. “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 Omicron specific variant vaccine (mRNA-1273.529) is expected to advance into clinical trials in early 2022.

The Company also announced data from a phase 2/3 study evaluating the 100mcg booster dose of mRNA-1273 in 305 individuals. The 100mcg booster dose was found to be generally safe and well tolerated. Adverse reactions reported after the booster were comparable to those observed following the 2-dose primary series.