Pfizer and Moderna Begin Omicron Vaccine Trials

Both Pfizer and Moderna have started clinical trials for their respective Omicron COVID-19 variant vaccine.

On Jan. 26, 2022, Moderna announced that they had dosed their first patient in a Phase II study of an Omicron specific booster vaccine candidate of their SpikeVax vaccine. Similarly, on Jan. 25, 2022, Pfizer and BioNTech announced the initiation of a clinical study into an Omicron-specific variant of their vaccine.

The Moderna study will feature two cohorts of participants receiving mRNA-1273, Moderna’s COVID-19 vaccine booster specifically tailored for the Omicron variant. One group includes participants who received the primary vaccine doses and a booster (with the booster dose being administered at least three months prior), while the other group is composed of individuals who only received the two-dose primary series (completed at least six months before the booster).

Conversely, the Pfizer study will feature three groups:

  • 615 individuals who received two doses of the current Pfizer-BioNTech COVID-19 vaccine 90–180 days prior to enrollment; they will receive one or two doses of the Omicron-based vaccine
  • 600 individuals who received three doses of the current Pfizer-BioNTech COVID-19 vaccine 90–180 days prior to enrollment; they will receive one dose of the Omicron-based vaccine
  • 200 vaccine-naïve participants will receive three doses of the Omicron-based vaccine

"We are reassured by the antibody persistence against Omicron at six months after the currently authorized 50 µg booster of mRNA-1273. Nonetheless, given the long-term threat demonstrated by Omicron's immune escape, we are advancing our Omicron-specific variant vaccine booster candidate and we are pleased to begin this part of our Phase [II] study," said Stéphane Bancel, CEO of Moderna, in a company press release. "We are also evaluating whether to include this Omicron-specific candidate in our multivalent booster program. We will continue to share data with public health authorities to help them make evidence-based decisions on the best booster strategies against SARS-CoV-2."

“While current research and real-world data show that boosters continue to provide a high level of protection against severe disease and hospitalization with Omicron, we recognize the need to be prepared in the event this protection wanes over time and to potentially help address Omicron and new variants in the future,” said Kathrin U. Jansen, senior vice-president and head of Vaccine Research & Development at Pfizer, in a company press release. “Staying vigilant against the virus requires us to identify new approaches for people to maintain a high level of protection, and we believe developing and investigating variant-based vaccines, like this one, are essential in our efforts to towards this goal.”

Source: Moderna, Pfizer