The pandemic H1N1 influenza vaccine results in low rates of seroconversion for patients with hematological malignancies
Department of Medicine, Division of Hematology, University of Western Ontario, London, ON, Canada. Leukemia & lymphoma
(Impact Factor: 2.89).
06/2011; 52(9):1736-41. DOI: 10.3109/10428194.2011.584003
Patients with hematological malignancies are at increased risk of influenza and its complications, but evidence for the efficacy of influenza vaccination in this population is limited. We sought to determine whether patients being treated for hematological malignancies were able to mount protective antibodies to the H1N1 influenza vaccine. Pre- and post-vaccination plasma samples were collected from patients with hematological malignancies during the 2009-2010 influenza season. Seroconversion was defined as a four-fold increase in antibody titer, as measured by the hemagglutinin inhibition test. Sixty-two patients received the H1N1 vaccine and 41 patients were unvaccinated controls. The rate of seroconversion among vaccinated patients was 21%, which was significantly higher than that in unvaccinated patients (0%), but significantly lower than that previously reported for healthy adults. Physicians should be aware that influenza vaccination may not generate an immune response in patients with hematological malignancies. Larger studies are required to confirm these results.
Available from: Abbas F Jawad
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Pediatric oncology patients represent a cohort of individuals uniquely at risk of complications from influenza, yet less likely to respond to the vaccine. It is not yet clear how to best protect this vulnerable population.
We performed a prospective analysis of 177 pediatric oncology patients to define the predictors of influenza vaccine responses. Each variable was examined over three time points and a repeated measure analysis was performed.
Patients with ALL vaccinated during induction phase had superior influenza vaccine responses than those subjects vaccinated during post-induction or maintenance phases (P=0·0237). Higher aggregate HAI titer responses were associated with a higher baseline B-cell count (P=0·0240), and higher CD4 and CD8 influenza-specific T-cell responses, suggesting prior antigen exposure is a significant contributor. The solid tumor cohort had equivalent responses during all time frames of chemotherapy.
The optimal protection from influenza of pediatric patients on chemotherapy should include vaccination, but it is clear that not all patients produce high titers of antibodies after vaccination. This study identified biomarkers that could be used to individualize vaccine approaches. Immunologic predictors might have a role in targeting resources, as B-cell counts predicted of vaccine responses among the patients with ALL.
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ABSTRACT: Patients with hematological malignancies are more susceptible to viral infections including influenza. In 2009, the World Health Organization classified the novel influenza A (H1N1) virus as pandemic. The potential impact of this pandemic for patients with hematological disorders was unknown. Institutional guidelines recommended two doses of AS03-adjuvanted influenza A (H1N1) 2009 pandemic vaccine for these patients.
We aimed to determine the safety, immunogenicity, and clinical efficacy of this vaccine in patients with hematological diseases. Furthermore, we compared the immunological responses to that obtained by the non-adjuvanted trivalent seasonal influenza vaccine (TIV).
All included patients received adjuvanted pandemic vaccine and the majority received TIV. Serum for antibody analyses was collected at five time points.
Thirty-one patients with different hematological diseases were included. After the second vaccine dose, a total of 25 (81%) reached both protective levels of antibodies and seroconversion response. Antibody titers ≥ 1 : 40 persisted for 50% of responding patients at 1 yr. Seroconversion was observed in 69% of 14 patients who had undergone hematopoietic stem cell transplantation and in all (9/9) patients with myeloma (five with ongoing treatment including high-dose corticosteroids). After vaccination with TIV, seroconversions against the three included strains were detected in 28%, 40%, and 20%. Response to the adjuvanted pandemic vaccine was superior (P < 0.009).
A substantial proportion of patients with hematological malignancies including patients undergoing chemotherapy mounted a good response to the adjuvanted pandemic vaccine. This vaccine had superior immunogenicity as compared to the non-adjuvanted TIV.
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ABSTRACT: Patients with central nervous system (CNS) malignancies represent an "at-risk" population for contracting influenza, particularly if they are receiving ongoing chemotherapy, radiation, and/or glucocorticoid treatment. The Centers for Disease Control endorses vaccination for these patients, although data are not available to indicate whether they mount an immunologic response adequate to achieve clinical protection.
A pilot prospective cohort study was designed to evaluate the immunogenicity of the standard-dose trivalent inactivated influenza vaccine in patients with malignant CNS tumors. Baseline data collection included diagnosis, chemotherapy, timing of chemotherapy or radiation relative to vaccination, and glucocorticoid dose. Serum samples were collected at baseline, day 14, day 28, and month 3 following vaccination. Samples were tested using hemagglutinin inhibition to determine seroconversion (4-fold rise in titer) and seroprotection (titer >1:40).
A total of 38 patients were enrolled (mean age, 54 years ±13.5 years, 60.5% male, 94.7% Caucasian, and 5.3% African American). CNS tumor diagnoses included glioblastoma multiforme (55.2%), other high-grade glioma (13.2%), low-grade glioma (15.8%), and primary CNS lymphoma (15.8%). At enrollment, 20 patients (52.6%) were taking glucocorticoids, 25 (65.8%) were on active chemotherapy, and 3 (7.9%) were undergoing radiation. Seroconversion rates at day 28 for the A/H1N1, A/H3N2, and B strains were 37%, 23% and 23%, respectively. Seroprotection was 80%, 69%, and 74%, respectively. All rates were significantly lower than published rates in healthy adults (P < .001).
Influenza vaccine immunogenicity is significantly reduced in patients with CNS malignancies. Future studies are needed to determine the causative etiologies and appropriate vaccination strategies.
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