US drugmaker Moderna says its booster shot effective against Omicron

US drugmaker Moderna on Monday announced that its booster shot increases neutralising antibodies against the new vaccine evading Omicron variant, compared to two doses.

An authorised dose of 50 microgram booster increased neutralising antibody levels against Omicron by approximately 37-fold compared to pre-boost levels, the company said in a statement.

"The dramatic increase in Covid-19 cases from the Omicron variant is concerning to all. However, these data showing that the currently authorised Moderna Covid-19 booster can boost neutralising antibody levels 37-fold higher than pre-boost levels are reassuring," said Stephane Bancel, Chief Executive Officer of Moderna, in the statement.

The company added that doubling the booster dose to 100 microgram increased neutralising titers 83-fold higher than pre-boost levels.

The results haven't been peer reviewed yet. The company plans to share the data with government health officials.

While the 100 microgram booster dose was "generally safe and well tolerated", however, there "was a trend toward slightly more frequent adverse reactions" following it compared to the authorised dose.

The company said it will also continue to develop an Omicron-specific booster candidate which should enter clinical trials in early 2022.

The hyper mutated Omicron variant of concern is spread so far to about 90 countries, raising serious concerns about the reduced vaccine efficacy and the increased risk of reinfection.

A third shot of Covid vaccine from Pfizer has also shown to provide significant protection against the new Omicron variant, according to study by the Israeli researchers.

However, a booster dose of Covid developed by China's Sinopharm has shown to generate weaker immune responses against Omicron.

A yet-to-be peer reviewed study led by researchers from Shanghai Jiao Tong University showed that neutralising antibody activity of a Sinopharm BBIBP-CorV booster against Omicron showed a 20.1-fold reduction, compared with its activity against a Wuhan strain.