The National Institute of Infectious Diseases estimated that the number of patients nationwide totaled around 1,118,000 during the same period. The rapid spread reflects lowered influenza immunity after cases had dropped in recent years amid anti-infection measures implemented against the coronavirus pandemic. Health experts say that fewer people have immunity against influenza since restrictions over the COVID-19 were lifted earlier this year, and that the influenza virus is spreading about a month earlier than normal. Coronavirus cases have also been increasing for the third consecutive week, authorities said. Experts have called for caution amid fears both viruses could spread further as year-end and New Year's social gatherings take place in Japan. School-wide and class-specific closures have taken place at 6,382 educational facilities nationwide in the week through Sunday, the ministry said.