U.S. biotechnology firm Moderna Inc. said Wednesday new clinical data on an experimental coronavirus vaccine showed effectiveness against the Omicron variant, making it the company's lead candidate for distribution as a fall booster shot.

According to the data, a booster dose of the latest vaccine increased Omicron-fighting antibodies approximately eight-fold, one month after its administration, when compared to the original version.

File photo shows a vial of COVID-19 vaccine developed by Moderna Inc., taken on May 24, 2021, in Japan. (Kyodo)

"We anticipate more durable protection against variants of concern," Moderna CEO Stephane Bancel said in a press release, noting the company will be submitting the preliminary data and analysis on the COVID-19 booster candidate to regulators with the hope it will be available in late summer.

The so-called "bivalent booster" is meant to work against both the original strain of the novel coronavirus and the Omicron variant, which is now dominant in the United States.

The study enrolled more than 800 people who have already received three shots, with 377 administered a fourth dose of the original vaccine and 437 the new version, the company said.

The safety and the side effects were consistent with the prior booster dose of the original vaccine, it said.

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