The US Food and Drug Administration (FDA) is leaning toward authorizing half-dose booster shots of the Moderna Inc COVID-19 vaccine, Bloomberg News on Tuesday, citing people familiar with the matter.

The FDA had been seeking information about the effectiveness of a full third dose of the Moderna vaccine, but is now ready to move forward and consider the half-dose booster Moderna has proposed, the report said.

Moderna and the FDA did not immediately respond to Reuters request for comment outside regular business hours.

Moderna on Sept. 1 submitted its application to the US Food and Drug Administration seeking authorization for a booster shot.

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The original Moderna vaccine contains 100-micrograms of mRNA in each shot. The company's submission to regulators to authorize a half-dose booster would allow Moderna to produce more.