In 2017, the decree issued by Ms Lorenzin Secretary of health increased the number of compulsory vaccinations, divided public opinion and the main political forces. Two coalitions faced each other. The first one, in favour of compulsory vaccinations, was led by institutional actors and supported by the majority of the scientific community. The rival coalition was composed of many associations and informal groups in favour of «vaccine freedom».The groups supporting mandatory vaccination relied mainly on their technical resources, while the no-vaccine movement made greater use of political resources. The institutional actors played a major role in framing the problem and drafting the decree. The opponents to the Lorenzin decree started mobilizing during the parliamentary debate, but they became more combative after the conversion law was passed.