Until 1854, vaccination acts had their origins in private member's bills and were aimed at increasing the numbers of children vaccinated. Thereafter, all public vaccination bills for England and Wales were drawn up within government departments or by practitioners with close ties to Whitehall. The goals of legislation also changed: toward enforcing compulsion and to imposing close and active supervision of vaccination by medical experts within central government. In this respect, public vaccination policy therefore followed wider patterns of government growth: in the 1850s and 1860s, a range of government departments employed experts to assist their administration and to inspect schools, factories, and some forms of transport. The shift in vaccination policy also reflected a desire to reform public health practice: to end a piecemeal approach of legislating on different health issues, and introduce “state medicine”: a coordinated national administration able to ensure proper standards of practice and provision in all health matters. The peculiar character of public vaccination—a national, fairly uniform system of provision, established under some degree of central control through the poor law authorities—left it particularly open to centralization, and it therefore became an important arena for attempts to create a hierarchical administration led by medical experts. However, the expert supervision of public vaccination was not created without difficulty. John Simon—the chief architect of vaccination policy from 1856—faced stern opposition from MPs, the antivaccination movement, and practitioners skeptical of the value of inspection.