%u2018What%20We%20Did%20Before%20Just%20Isn%u2019t%20Working%u2019%3A%20Delta%20Variant%20Threatens%20to%20Overwhelm%20Russia%20-%20The%20Moscow%20Times

On June 10, the chief doctor of Moscow's flagship Covid-19 hospital, Denis Protsenko, told the Echo Moskvy radio station that patients were not responding to previously effective treatments.