A true post-apocalyptic story, humans... screwed it up! An 'accident' (explained later in book) happened, rendering all larger mammals sterile. So, what happens to humanity when there's it's at an end? This is the story of Algy aka Greybeard, one of the 'young', aka a 60+ year old normal man and his wife as they live through the accident (they were kids), and beyond. Normal as in, he's not a super-genius (or supervillain!), he's just a good guy trying to get by as humanity comes to terms with extinction. As one can imagine, there are some who aren't so good, or doing bad because they think it's for the good. Yes, it's somewhat like Children of Men (movie and book (P.D. James)), but this book precedes it by a few decades (1964 v 1992). Some say Children of men ripped it off, but, having only seen the movie, I can't say for certain, other than they both about what happens if we go sterile, and both are set in England in the same time period.

Having lived through this pandemic and seen all the silly crap that a large fraction of the population has done/believed in, I'd say he's not too far off in his prediction on 'what if humanity becomes sterile'.