Abstract
The declaration of the influenza A (H1N1) epidemic in late April 2009 in Mexico was followed by a series of criticisms and to a lesser degree shows of support of the measures applied and of the manner of operation of the Mexican health system. In this text, I attempt to explain, using materials published in medical journals and in the Mexican press, the technical and ideological assumptions behind the work undertaken by the health sector as well as the assumptions behind the criticisms received. This exploration has two complementary objectives: first, to understand why the Mexican health sector acted the way it did; and second, to consider the technical legitimacy of the actions developed by the health sector and of the criticisms made regarding those actions.