Pfizer and BioNTech’s Covid-19 vaccine is just 39% effective in Israel where the delta variant is the dominant strain, but still provides strong protection against severe illness and hospitalization, according to a new report from the country’s Health Ministry.
The efficacy figure, which is based on an unspecified number of people between June 20 and July 17, is down from an earlier estimate of 64% two weeks ago and conflicts with data out of the U.K. that found the shot was 88% effective against symptomatic disease caused by the variant.
Might not be that the 39% figure holds outside of Israel since they were one of the first countries to do widespread vaccination
It's not a whole book, but chapter 8 from History of the CPSU(B) that covers that whole period. It's also not super long: https://www.marxists.org/reference/archive/stalin/works/1939/x01/ch08.htm
And here's a text-to-speech recording of the chapter: https://youtu.be/CICY79HKEYo