To understand the French public’s response to the 2009 pandemic A/H1N1 influenza health threat a sequence analysis framework has been employed mobilising different theoretical strands such as innovations diffusion theory, surprise theory and social representation theory. These tend to suggest that disease episodes, public health policy and the public’s response should be considered within a larger socio‐cognitive frame incorporating representations anchored by prior disease episodes and campaigns. It is suggested in this article that the public’s response was greatly influenced by the pervasive anchoring of the social representations of the pandemic threat to the 1918 Spanish flu in the lay and scientific media. These representations were eventually seen not to match the reality of the disease and consequently the French public did not panic during the 2009 pandemic. This hypothesis has been tested empirically by examining retrospective media, bibliographical data and an analysis of risk perception carried out through three cross‐sectional studies prior to and during the pandemic episode and one month after the launch of the vaccination campaign. These findings suggest that alarmist framings of health threats may be counterproductive since they may reduce the capacity of public health organisations to mobilise the public in the case of more serious emerging disease.