Per the review in The New Yorker

Biss also probes the insistence on physical purity, which, she argues, underlies vaccine anxiety. As a new mother herself, she confesses to feeling overwhelmed by the threat of toxins, from phthalates to mercury to B.P.A., and says that “people like me” tend to view toxins, instead of germs, as “the root cause of most maladies.” Still, she notes that children’s exposure to chemicals such as formaldehyde is much lower from vaccines than it is from other common sources in the environment, and that the preservative thimerosal, which contains mercury, has been almost entirely removed from vaccines administered to young children in the United States (with the exception of some flu shots). Biss acknowledges that toxins can pose risks at sufficiently high levels, but she worries that an extreme obsession with bodily purity comes at its own price. “Quite a bit of human solidarity has been sacrificed in pursuit of preserving some kind of imagined purity,” she writes, invoking historical laws against sodomy and the forced sterilization of poor women. (Her analogy is something of a false one. Individual purity is different from racial purity. Yet Biss’s flamethrowing moments, like this oblique comparison between vaccine refusers and eugenicists and bigots, tend to sneak up on readers in the midst of her more meandering literary analysis, which is part of what gives them power.)

Extras:

“We are all already polluted,” Biss writes. “We are, in other words, continuous with everything here on earth.  Including, and especially, each other.”