According to many studies, health care staff who are not vaccinated are the main cause of flu contamination within a hospital during an epidemic. In Quebec, Canada, the majority of health care staff (89%) are now being vaccinated, thus protecting patients from contamination. In France, the public health organisation «Haute Autorité de Santé», composed of experts and recognized health authorities, issued the following statement on September 7th. «Health care professionals refusing to be vaccinated run the risk of being the first link in the chain of nosocomial contamination».