3. To determine the possibility of predicting the frequency of adverse reactions attributed to the Vaccine pandemic Sanofi To (H1N1) evaluated in adult Mexican population. The response will be evaluated of seroconversión (I increase in the titles in four times with regard to the level basal), seropositividad (titles(degrees) overhead of 1:40) and titles(degrees) to geometric averages. The patients will be analyzed in the group in which they were randomized (intention of treatment). The information will be tried using the statistical package SPSS, version 10.1.