Moderna begins phase 2 trial of Omicron-specific booster

Moderna has begun a phase 2 study of their Omicron-specific booster (mRNA-1273.529).

The phase 2 study will include two groups. The first group includes those who’ve had two doses of the vaccine, while the second includes those who’ve had two doses of the vaccine as well as a booster shot (mRNA-1273).

The phase two study follows on from previous trials, and assesses the safety and effectiveness of the Omicron-specific booster in adults aged 18 and over.

Moderna plans to enrol approximately 300 people in each group, and studies will be conducted in up to 24 sites in the US.

Currently, Moderna’s authorised booster increases neutralising antibodies against Omicron by about 37-fold. This is compared to the pre-booster data levels and a 100µg dose of mRNA-1273 which demonstrated an increase in neutralising antibodies by about 83-fold compared to pre-boost levels.

Stéphane Bancel, chief executive officer of Moderna, said: "We are reassured by the antibody persistence against Omicron at six months after the currently authorised 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.”

Bancel added: "We are also evaluating whether to include this Omicron-specific candidate in our multivalent booster programme. 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."

Data showing protection levels against Omicron six months after being given a booster shot has been published in The New England Journal of Medicine.