|| The campaign against the flu is carried out in September and October. Before this the laboratory investigates the kind of virus expected for each year and they prepare the appropriate vaccine. The vaccine is opportune for the old and those with a chronic illness. Also for doctors and teachers who tend to be in contact with large numbers of people. The aim of the vaccine is to avoid getting the flu. However, sometimes, a different epidemic than the one expected can appear and then the vaccine has no effect. In any case, it is a good idea to get the vaccine as the chronic ill people have had less complications during these last few years.