Once again, COVID-19 cases are surging across Japan, fueled in part by the newer, immunity-escaping omicron subvariant BA.5, raising concerns that the nation’s seventh wave has begun.

Nationwide, daily new infections topped 45,000 on Wednesday — nearly double the figure from last week and on par with the level seen in mid-May. The surge comes as people are planning summer holidays and large, in-person events have begun to return. At the same time, the number of ambulance calls due to heatstroke is growing.

The government has ruled out the possibility of imposing quasi-emergency measures any time soon, but it is considering whether to expand its vaccination program so that fourth shots — currently administered only to those at-risk and residents age 60 or older — can be offered to more people. Some experts, meanwhile, have also urged the government to swiftly make the fourth dose available to medical and nursing care workers in order to prevent cluster infections on the front line.