This study applies conversation analysis to an infant/caregiver activity, "getting vaccinated." Here, an infant’s natural reactions (crying) to pain (inoculations) appear to function as inchoate social devices aiding the co-creation of an emerging proto-social interaction order. I argue and demonstrate that the infant’s cries comprise its (biological, as opposed to psychological) devices that contribute to the proto-interaction order, when systematically responded to by caregivers, and thus (inadvertently) employed as interactional resources. The caregivers’ responses to the crying demonstrate that the participants’ actions, including the infant’s, constitute resources for creating a proto-social-interaction order from the interacting normative and biological rule systems. Finally, since conversation analysis has not traditionally been applied to infant/caregiver interaction, I contrast relevant conversation analyses to developmental psychological studies.