Finnish researchers develop nasal spray COVID-19 vaccine(1/2)

This undated and unlocated photo shows a researcher places a sample of the nasal spray COVID-19 vaccine into a laminar flow cabinet that provides sterile working environments. A nasal spray COVID-19 vaccine based on gene transfer technology can be adapted flexibly to tackle new variants of coronavirus, Finnish researchers announced on Monday. (Xinhua/Agencies)

This undated and unlocated photo shows a researcher places a sample of the nasal spray COVID-19 vaccine into a laminar flow cabinet that provides sterile working environments. A nasal spray COVID-19 vaccine based on gene transfer technology can be adapted flexibly to tackle new variants of coronavirus, Finnish researchers announced on Monday. (Xinhua/Agencies)