The author addresses the issue of the constitutional limits to the determination of sanitary measures in case of eradication of infectious diseases, taking account of the ones taken to tackle Covid-19. Taking the view that balancing the conflict between public health and citizens’ autonomy cannot be done in absolute terms, the author analyses to this respect the decision taken by the Supreme Federal Court of Brazil on December 17, 2020 concerning the constitutionality of mandatory vaccination. She afterwards addresses the relationship between the employers’ will or duty to protect workers’ health and the consequences of workers refusing to be vaccinated.