Unlike normal seasonal flu, the H1N1 virus appears to be disproportionately infecting older children and young adults. So far the largest number of confirmed cases have occurred in people between the ages of five and 24.

If the vaccinations are for those only up to 40 years of age then it's not really the entire population. I personally know of 7 people including myself who are definitely over 40. In fact we are all over 50.