[4] Reich spent nearly ten years exploring what motivates some parents to decline inoculations for their children, or delay them.

She sees vaccine hesitancy as a consequence of societal pressures on parents (especially middle-class mothers) to make choices that are uniquely suited to their own children in terms of health and education, to maximize their chances of success in life: "We do vaccines in a way that has been shown to be scientifically the most efficacious and the safest and also the easiest to distribute at a national level.

"[5][6] Working full-time on their kids, these parents are inclined to disregard generic advice dispensed by health professionals.

[7][8] Facing a steady stream of misleading information, pediatricians and public health professionals have to know what motivates parents to be reluctant about vaccines, and to adjust how they communicate, says Reich.

How to put the focus on collective benefits - explaining own inoculation better protects all children - may be a way for public health authorities to overcome the reluctance of many parents.