The Osaka prefectural government in western Japan says it will launch research into whether gargling with medicine could reduce the amount of the coronavirus in saliva, making the person less infectious.

Osaka Governor Yoshimura Hirofumi on Tuesday cited a recent study that indicated gargling with the mouthwash may help reduce coronavirus infections.

A medical society in Japan is to research lingering symptoms that some people suffer after recovering from COVID-19 and testing negative.

Members of the Japanese Respiratory Society plan to begin collecting data on infected people from medical institutions across Japan as early as next month.

An NHK survey has found that COVID-19 has lingering effects on some patients after testing negative for the virus and being discharged from hospital.

Hospital doctors treating coronavirus patients say people should know that various problems can persist after patients' discharge from hospital. They also say they hope for a wider network of support to be created for those people.