Moderna announced its 3-fold approach to addressing SARS-CoV-2 variants of concern in light of the emergence of the Omicron (B.1.1.529) variant.

The Company is currently testing a higher dose booster (100µg) of its COVID-19 vaccine, mRNA-1273, in 306 individuals in a safety and immunogenicity study. Sera from high dose booster recipients will now also be tested to see if the 100µg dose provides protection against Omicron.

Additionally, 2 multivalent booster candidates are being investigated. The mRNA-1273.211 vaccine includes several mutations present in the Omicron variant and is being studied at both the 50µg (N=300) and 100µg (N=584) dose levels.

Continue Reading

The second candidate, mRNA-1273.213, includes mutations present in the Omicron variant that were also seen in the Beta and Delta variants. Both dose levels are expected to be explored in this study.

Sera from these booster studies will be tested to determine if these multivalent booster candidates provide protection against Omicron.

As part of Moderna’s larger strategy to provide variant-specific candidates for emerging variants of concern, a new booster candidate specific for Omicron is also being planned.

“The mutations in the Omicron variant are concerning and for several days, we have been moving as fast as possible to execute our strategy to address this variant,” said Stéphane Bancel, Chief Executive Officer of Moderna. “We have 3 lines of defense that we are advancing in parallel: we have already evaluated a higher dose booster of mRNA-1273 (100µg), second, we are already studying 2 multivalent booster candidates in the clinic that were designed to anticipate mutations such as those that have emerged in the Omicron variant and data is expected in the coming weeks, and third, we are rapidly advancing a Omicron-specific booster candidate (mRNA-1273.529).”

The Omicron variant was first reported to the World Health Organization (WHO) by South Africa. While no cases have been detected in the US thus far, the White House has ordered air travel restrictions from South Africa and 7 other countries.

In a briefing with President Biden, Chief Medical Advisor Dr Anthony Fauci noted that it would likely take about 2 weeks for more information on the transmissibility and severity of the variant to be available. He reiterated the importance of vaccination as being the best means of protection against severe COVID-19 disease while additional data on Omicron is being gathered.


  1. Moderna announces strategy to address Omicron (B.1.1.529) SARS-CoV-2 variant. News release. Business Wire. November 26, 2021.
  2. Centers for Disease Control and Prevention. CDC statement on B.1.1.529 (Omicron variant). Accessed November 26, 2021.
  3. The White House Briefing Room. Statement by President Joe Biden on the Omicron COVID-⁠19 variant. Accessed November 26, 2021.
  4. The White House Briefing Room. Readout of President Biden’s meeting with COVID-⁠19 Response Team on the Omicron variant. Accessed November 28, 2021.

This article originally appeared on MPR