MixedThe Boston GlobeWadman’s research is extensive, and her book is packed with anecdotes and details of the science, the times, and the people. But many readers may find descriptions of Hayflick’s work overly detailed or wonder whether the backstories of incidental characters add much. And some may wish, especially in the first part of the book, that Wadman pruned and pared more aggressively. The race promised in the title does materialize, but it’s a bit of a slow build. Still, The Vaccine Race recalls a breakthrough that has faded in our collective memory, owing to its success in all but eliminating a major cause of birth defects across a wide swath of the world.