Why did Japan’s fifth and biggest wave of the coronavirus pandemic, driven by the supercontagious delta variant, suddenly come to an abrupt end following a seemingly relentless rise in new infections?

A certain mutation in the COVID-19 Delta variant causes infected cells to form disruptive chunks in the lungs and leads to more serious symptoms of the disease, a research team said. If the cells in ...

The coronavirus isolated by the National Institute of Infectious Diseases is seen in this electronic microscope photograph provided by the institute. CHIBA -- While omicron variant coronavirus cases ...