TORONTO/CHICAGO : The modified common cold viruses behind high-profile COVID-19 vaccine candidates from China's CanSino Biologics and Russia's Gamaleya Institute have been studied for decades, but are still not widely used.The following are some details of their development, how they work and past and potential future uses:When were these viruses first used in medical research?The modified adenovirus type 5 (Ad5) viruses used in these vaccines were first created by Canadian researcher Dr.
Frank Graham at a Dutch lab in the 1970s.Graham planned to use them to study mechanisms underlying cancer, and distributed the human kidney cell line that makes them, called HEK293, to researchers all over the world."The cells became tremendously.