A method for testing whether a patient will respond therapeutically to administration of an immunogenic composition or for predicting whether a patient will survive longer after administration of an immunogenic composition. The method comprises the step of: - Measuring the levels of activated Natural Killer (NK) cells in a blood sample from the patient, wherein low levels of activated NK cells indicate that the patient will develop a prophylactic or therapeutic immune response towards the immunogenic composition or that the patient will have a longer survival rate. Low levels of activated NK cells is less than about 5% of peripheral blood lymphocytes which express CD16, CD56 and CD96 surface antigens.
