Immunogenicity of influenza vaccine in patients with hemato-oncological disorders

The aim of this study was to measure the production of antihemagglutinin and antineuraminidase antibodies in patients with proliferative diseases of the hematopoietic or lymphatic system, immunized with influenza vaccine in the epidemic season 1995/96. Twenty patients between 22 and 84 years volunteered for vaccination and were vaccinated subcutaneously with a single dose of split trivalent influenza vaccine ("Fluarix", SmithKline Beecham) in autumn 1995 at the outpatients clinic, General Hospital, Toruń, Poland, where they were being treated with anti-cancer chemotherapy. The vaccine consisted of a 0.5 ml dose containing 15 microg hemagglutinin (HA) of each of the following strains: A/Singapore/6/86 (H1N1), A/Johannesburg/33/94 (H3N2) and B/Beijing/184/93. Neuraminidase activity amounted to 17.24x10(-3) U/ml. Antibody production was determined in sera collected before vaccination, 10 days and 28 days after vaccination by the hemagglutinin inhibition test (HI) and neuraminidase inhibition test (NI). Mean fold increase values after vaccination were statistically significant in patients undergoing cytostatic treatment. After 28 days mean fold increase of antihemagglutinin antibodies ranged from 7.9 to 25.2, while in the case of antineuraminidase antibodies these values were between 12.4 and 14.3. It is notable that no adverse reactions were observed after immunization and none of the patients was infected with influenza virus, in spite of the fact that there was a local epidemic in the Toruń region when the study was carried out. The results presented in this paper confirm the beneficial effect of influenza vaccination in high-risk groups of patients with proliferative diseases of the hematopoietic and lymphatic systems.