Immune response after a single vaccination against 2009 influenza A H1N1 in hemodialysis patients

Background: Influenza infection is a significant cause of morbidity and mortality in general population. Hemodialysis patients are considered at high risk of influenza infection given their altered immune status. Pandemic influenza virus is new for human beings, so it is hard to predict the response to infection or vaccination. We aimed to evaluate the response to pandemic H1N1 vaccination in hemodialysis patients. Methods: A total of 70 patients on chronic hemodialysis and 20 controls who had been vaccinated against the pandemic influenza virus 5 weeks before the time of blood sampling were included into this study. The anti-H1N1 immunoglobulin G (IgG) antibodies of the patients were studied with enzyme immune assay (EIA) method. Our cut-off optical density (OD) value was 1.503. If the patient’s OD value was equal or higher than this value, it was considered as positive. If it was lower, it was considered as negative. Results: The mean OD value was 2.22 ± 0.42 in the patient group and 1.99 ± 0.34 in the control group (p < 0.05). Two of 70 patients and 1 of the controls had negative OD values and they were considered as nonresponsive to vaccination. There was also a negative correlation between the age and OD values in the patient group (r = −0.277, p < 0.05). Conclusion: H1N1 vaccine can be performed safely and cost effectively with a single dose to the risk groups especially to the hemodialysis patients. Evaluation of H1N1 IgG antibody with enzyme-linked immunosorbent assay (ELISA) may be a safe, easy, and cost-effective assay.