The head of the Japanese government's advisory panel on the coronavirus response has said its top priority is preventing a rebound in new infections until around June, when local governments will likely have received enough vaccine doses for their elderly citizens.

Omi Shigeru spoke at a news conference on Thursday. The government decided earlier in the day to allow the prefectures of Osaka, Hyogo, and Miyagi to take stronger anti-virus measures without an emergency declaration.

Omi said other areas may need similar arrangements in the future. He said the panel will guide local officials to flexibly make decisions based on objective assessments.

Omi said cluster infections have recently occurred not only at dining establishments but also at students' parties and other gatherings, as well as in factories, schools, international communities, and karaoke cafes.

He said people are less willing to lower infection risks by changing their behavior, and more contagious virus variants could hasten the spread of infections.

He underscored the need for central and local government officials to implement a set of anti-virus measures.

The set should include asking dining establishments to shorten their business hours, inspecting such facilities, urging people not to travel across prefectural borders, and calling on people to refrain from using karaoke cafes.

Omi stressed group dining should take place at establishments where anti-infection measures are in place, and the number of participants should be limited to four.

He also called on people to avoid closed, crowded, and close-contact settings.

Omi urged people to wear masks while having conversations, even in restaurants, and to refrain from attending large drinking parties.