1355. A Pilot Randomized Controlled Trial of Adjuvanted vs. Nonadjuvanted Influenza vaccine in Adult Allogeneic Hematopoietic Stem Cell Transplant Recipients
Session: Poster Abstract Session: Clinical Trials
Friday, October 28, 2016
Room: Poster Hall
Background:

The annual influenza vaccine is recommended for haematological stem cell transplant (HSCT) recipients although studies have shown suboptimal immunogenicity for the standard vaccine. Influenza vaccine containing an oil-in-water emulsion adjuvant (MF-59) may lead to greater immunogenicity in hematological stem cell transplant recipients.

Methods:

We conducted a randomized controlled trial comparing the safety and immunogenicity of adjuvanted versus nonadjuvanted influenza vaccine in adult allogeneic HSCT patients. Patients who were ≥12 weeks post-transplant were randomized 1:1 to receive the 2015-16 influenza vaccine with or without MF59 adjuvant. Both vaccines contained 15µg each of A/California/7/2009 (H1N1)pdm09, A/Switzerland/9715293/2013 (H3N2), and B/Phuket/3073/2013. Preimmunization and 4-week postimmunization sera underwent strain-specific hemagglutination inhibition assay.

Results:

We randomized 73 patients and 67 (35 adjuvanted; 32 nonadjuvanted) had complete samples available at follow-up. Median age was 54 years (range 22-74) and time from transplant was 380 days (range 85-8107). Concurrent graft versus host disease (GVHD) occurred in 42/73 (57.5%). Baseline seroprotection rates were 47.8%, 46.3%, and 43.3% for A/H1N1, A/H3N2, and B respectively. Seroconversion to at least 1 of 3 influenza antigens was present in 62.9% versus 53.1% for adjuvanted versus nonadjuvanted vaccine respectively (p=0.42). Seroconversion to A/H1N1, A/H3N2, and B was 31.4% versus 21.9%, 57.1% versus 40.6%, and 37.1% versus 25.0% in adjuvanted versus nonadjuvanted vaccine (p = 0.38, 0.18, 0.29) respectively. Pre- and post-vaccination geometric mean titers were similar between groups. Factors associated with lower seroconversion rates were antithymoglobulin usage within one year (p=0.03), use of calcineurin inhibitors (tacrolimus or cyclosporine) (p<0.001), and shorter duration from transplantation (p<0.001). Seroconversion rates were greater in patients who received previous year influenza vaccination (82.6% versus 45.5%, p=0.03). Concurrent GVHD was not associated with vaccine response (p=0.25). Local and systemic adverse events were similar for the two vaccines.

Conclusion:

Adjuvanted vaccine demonstrated similar immunogenicity to nonadjvuanted vaccine in allogeneic HSCT patients and may be an option for this population.

Yoichiro Natori, MD1, Atul Humar, MD1, Jeffrey Lipton, MD2, Dennis Kim, MD2, Katja Hoschler, PhD3, Peter Ashton, MSc1 and Deepali Kumar, MD1, (1)Transplant Infectious Diseases, University Health Network, Toronto, ON, Canada, (2)Division of Hematology and Oncology, University Health Network, Toronto, ON, Canada, (3)Public Health England, London, United Kingdom

Disclosures:

Y. Natori, None

A. Humar, Roche: Grant Investigator , Research grant

J. Lipton, None

D. Kim, None

K. Hoschler, None

P. Ashton, None

D. Kumar, Roche: Grant Investigator , Research grant
GSK: Grant Investigator , Research grant
Sanofi-Pasteur: Scientific Advisor , Speaker honorarium

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