A health ministry panel has endorsed a plan for Japan to introduce COVID-19 vaccines that target the XBB.1 sublineage of the omicron variant for a fresh inoculation drive in the fall.

The vaccine subcommittee under the ministry on Friday decided to update the vaccines, pending applications from vaccine-makers and ministry approval, to prepare for another spike in infections possibly arriving in the winter.

The country currently offers a bivalent COVID-19 booster targeting the original coronavirus strain and BA.1 sublineage of the omicron variant, or one targeting the original strain and the BA.4 and BA.5 sublineages of omicron. The free vaccination program ¡ª currently only covering people age 65 or older, people with underlying conditions and medical and nursing care workers ¡ª is scheduled to run through the end of August.

From September, Japan plans to start a fresh booster drive, this time covering everyone. The government will offer the shots for free at least through the end of March 2024.

As of June 5, XBB.1.5 ¡ª a subtype of XBB, a heavily mutated version of the omicron variant ¡ª is the dominant strain in many developed countries, followed by XBB.1.16 and XBB, according to Our World in Data statistics cited by the panel.

A similar trend has been observed in Japan, where the National Institute of Infectious Diseases estimated that XBB.1.16 made up 44% of all cases, followed by XBB (33%), XBB.1.5 (13%) and XBB.1.9 (8%) in the week through Sunday.

The panel said it is reasonable to update the boosters to one targeting just XBB, given recent research that shows the current bivalent booster targeting BA.4 and BA.5 does not produce as many neutralizing antibodies for XBB.1.5 as for BA.4 and BA.5, and considering the extremely small chance of the dominant strain reverting to the original coronavirus.

The panel¡¯s move follows the recommendation made in May by the World Health Organization¡¯s advisory group that this year¡¯s COVID-19 booster should target one of the currently dominant XBB variants, as well as the U.S. Food and Drug Administration advisory committee¡¯s move last week to endorse a booster shot targeting the XBB1.5 sublineage for the 2023-24 booster drive.