Immunogenicity Of Influenza Vaccination In Patients With Non-Hodgkin Lymphoma: Final Report After Two Epidemic Seasons.

Abstract Vaccination against influenza is recommended for immunocompromised individuals. However, there is little information concerning the efficacy of vaccination in patients (pts) with non-Hodgkin lymphoma (NHL). The purpose of this study was to assess humoral response to standard intramuscular trivalent subunit influenza vaccine in pts with NHL as compared to healthy subjects. In two consecutive epidemic seasons, 2003/2004 and 2004/2005, 163 pts and 92 healthy controls were vaccinated. Antibody titers to hemagglutinin (HA) and neuraminidase (NA) were measured in serum samples collected before vaccination, and 1 and 6 months apart. Changes in the hemagglutination inhibition (HAI) and neuraminidase inhibition (NII) antibody titers were assessed by comparing geometric mean titers and mean fold increases to baseline values and by comparing changes in the HA seroconversion and seroprotection rates. Pts who received influenza vaccine during 2003/2004 season had after one month increases in the geometric mean titers by a factor of 8,64–26,60 for HI and 6,93–12,66 for NI, as compared with respective increases by a factor of 9,12–24,41 and 4,83–10,31 for the healthy controls. At one month after vaccination seroprotection and seroresponse rates were similar in the two groups, ranging from 68,42 to 84,21 % and 71,93 to 94,74 % in NHL and 66,67–82,22 % and 62,22–86,67 % in controls, respectively. After six months, seroprotection and seroresponse rates had decreased in NHL group to 31,91–38,30% and 46,81–72,34%, respectively. Pts who received influenza vaccine during 2004/2005 season had after 1 month increases in the geometric mean titers by a factor of 38,76–41,49 for HI and 26,59–30,31 for NI, as compared with respective increases by a factor of 81,19–104,32 and 52,16–54,52 for the healthy controls. Seroprotection and seroresponse rates were lower in the former group, ranging from 62,11 to 65,26 % and 74,47 to 77,66 %, respectively. After six months, these parameters had decreased to 24,72–31,46% and 57,30–59,55%, respectively. In both studied seasons, pts achieved titres of functional antibodies greater than the protective threshold, irrespective of the previous chemotherapy administration. The results of this study indicate that standard influenza vaccination induces sufficient immune responses in pts with NHL. Previous chemotherapy adminstration seems to have no impact on the efficacy of vaccination.