Moderna vaccine
Vials with a sticker reading, "COVID-19 / Coronavirus vaccine / Injection only" and a medical syringe are seen in front of a displayed Moderna logo in this illustration taken October 31, 2020. Image Credit: Reuters

Moderna Inc said on Wednesday it had dosed the first participant in a mid-stage study testing a booster shot of its vaccine specifically tailored to the fast-spreading Omicron COVID-19 variant.

The company also reported data showing that neutralizing antibodies against the Omicron variant declined six months after a third booster dose of its original vaccine but remained detectable.

Moderna’s Phase 2 trial will test the Omicron-specific booster in adults aged 18 years and older.

It will study the booster in individuals who received only the two-dose primary series of Moderna’s original vaccine, mRNA-1273, and also in those who received the primary series and a booster dose of the same vaccine, the company said.

Pfizer and partner BioNTech earlier this month also started a clinical trial of their vaccine specifically designed to target the Omicron variant.