Stem cell and and heart transplant patients will receive pandemic H1N1 influenza vaccination according to the clinical guidelines. Two doses will be given, in 3-week interval.~In these patients we will measure the specific antibody production. Blood sample 5 ml will be drawn before the first vaccine, before the second, and 3-4 weeks after the 2nd dose.
Stem cell and and heart transplant patients will receive pandemic H1N1 influenza vaccination according to the clinical guidelines.~In these patients the investigators will measure the specific antibody production.