Moderna has said its COVID booster shot increases ‘Omicron-neutralizing’ antibody levels 37-fold – suggesting it is more effective than Pfizer.

The US-based company said the currently approved half-dose of Moderna boosts protection by a factor of 37, while a full dose would boost protection by a factor of 83.

Pfizer and BioNTech have previously said their booster offers 25-fold protection against the variant.

Moderna CEO Stéphane Bancel said the company is also working on an Omicron-specific vaccine which will go into clinical trials early next years.

“The dramatic increase in COVID-19 cases from the Omicron variant is concerning to all,” he said.

“However, these data showing that the currently authorized Moderna COVID-19 booster can boost neutralizing antibody levels 37-fold higher than pre-boost levels are reassuring.

“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.

“We will also continue to generate and share data across our booster strategies with public health authorities to help them make evidence-based decisions on the best vaccination strategies against SARS-CoV-2.”

The company said a full-dose booster had no more side effects than those experienced by people who got the first two doses.

The side-effects were slightly more frequent than for those who only got the half dose.

Shares in Moderna rose 6.5% in pre-market trading in the US following the announcement.