This article presents two cases of policymaking concerning the vaccine against Human Papilloma Virus (HPV), which is sexually transmitted and carcinogenic. Our analysis focuses on its introduction in Austria and the Netherlands. In both contexts, we find prevention and screening to be at once complementary and competing public health logics and we draw on the concept of 'infrastructure' to understand their roles in shaping the reception of the vaccine. We reveal how the HPV vaccine had to be made 'good enough', much like the Pap smear (Casper and Clarke ), by means of diverse tinkering practices that transformed both the technology and the infrastructures in which they emerged. At the same time, it was important that the vaccine would not come to problematise Pap smear-based screening. The article points to the contextually contingent nature of policymaking around new medical technologies, and the skillful care with which public health infrastructures such as immunisation and screening programmes are handled and tinkered with.