The Japanese government plans to roll out a new type of COVID-19 vaccine considered effective for the Omicron variant as early as October, sources familiar with the matter said Friday.

The so-called bivalent vaccine combines ingredients used for existing COVID-19 shots and those derived from the BA.1 subtype of the Omicron variant, and is expected to curb the spread of the BA.5 subvariant currently prevalent across the country.

The new vaccine is under development by U.S. pharmaceutical companies Pfizer Inc. and Moderna Inc. Their products were found to increase neutralizing antibodies against the BA.1 subvariant and were also effective for the BA.5 subtype to some extent, according to some reports.

The two companies are set to apply for authorization for their products to be used in Japan soon, according to the sources.

A health ministry panel to be held Monday will discuss whether Japan should introduce the new vaccine, the sources said.

The government plans to make it available to elderly people and those with preexisting conditions first as they are at higher risk of developing severe symptoms. Younger people may become eligible for the shot depending on how effective it proves to be.

Japan's daily infection tally soared to a record 249,830 on Wednesday, with the number continuing to climb since early July amid the seventh wave of the pandemic driven by the highly transmissible BA.5 subvariant.

The drug makers are also planning to roll out the new vaccine in Europe.