Update on influenza vaccination using microneedle delivery

Transcription

1 Mark Prausnitz serves as a consultant and is an inventor on patents licensed to companies developing products related to this presentation. This potential conflict of interest is being managed by Georgia Tech and Emory University Update on influenza vaccination using microneedle delivery Ioanna Skountzou Emory University School of Medicine Emory Vaccine Center

2 Enhanced humoral immune responses Increased duration of immunity Increased breadth of immunity Selected immunological advantages of skin immunization

3 Advantages of microneedle patch vaccine delivery Solid Metal Polymer Advantages Avoid hypodermic needles Painless Enhanced stability Rapid distribution Dose sparing Low cost Potential self-administration

4 How does microneedle-based immunization initiate immune responses? MN immunization results in an increase of cytokines produced by the skin resident populations important for neutrophils, monocytes and dendritic cells recruitment, which are key players in the innate immune response Langerhans cells The dermal immune system Dermal dendritic cells

5 Objective 1 Determine the effectiveness of seasonal influenza subunit vaccine strains encapsulated in dissolving microneedle patches in murine model. Objective 2 Determine contribution of Langerin+ cells in adaptive responses elicited by skin immunization with dissolving microneedle patches. Objective 3 Confirm vaccine stability in dissolving microneedle patches (in vitro and in vivo studies) Objective 4 Define efficacy of subunit vaccine in non-human primates after microneedle delivery

6 Objective 1: Efficacy of dissolving microneedles Vaccine and routes of delivery Gelatin microneedles A/Brisbane/59/7 (H1N1) A/Victoria/21/9 (H3N2) B/Brisbane/6/8 Cohorts of BALB/c mice were immunized once with 3 µg HA of monovalent vaccine intramuscularly (unprocessed vaccine, ; vaccine mixed with excipients, exc. ) or before 1 min cutaneously (, ) 1 min skin

7 Percent BW changes of survivors Percent survival Immunization with H1N1 vaccine conferred complete survival in all vaccinated cohorts Challenge with 5xLD5 mouseadapted A/Brisbane/59/ Days post-infection 11 9 Naive exc Naive exc Days post-infection

8 Percent BW changes of survivors Percent survival H3N2 vaccine conferred complete survival in cohorts, whereas and cohorts showed partial or no survival. Challenge with 5xLD5 mouseadapted A/Victoria/21/ Days post-infection Naive exc 11 9 Naive exc Days post-infection

9 Influenza B vaccine induced robust, long lasting immune responses by skin immunization Anti-B/Brisbane/6/8 NT titers (Gmean 95% CI) anti-b/brisbane/6/8 HAI titers Gmean 95%CI 512 a Naive a exc w k. 2 w k. 4 w k a,b a,b a,b Naive exc wk4 wk1

10 Rates of survival (%) Pixel intensity, % Conclusion 2: Langerin+ cells contribute to adaptive responses Langerin-DTR skin -DT +DT Western blot of HA in skin lysate V Antigen removal ± DT hr 24 hr 3% DT- DT- DT- DT+ vaccine retention in skin V: A/Brisbane/59/7 1-3: skin alone 4-6: skin at h 7-9: skin at 24h w/ DT 1-12:skin at 24h w/o DT Protective immunity ± DT Naive DT- DT Days post infection

11 Percent survival patch content, % from initial load (Mean + SD) Conclusion 3: Vaccine in is stable for at least 9 days at 25 o C Stability of HA in gelatin patches 15 * * * H1N1 H3N2 B Days in storage Protective immunity after 3 months at 25 o C 5xLD 5 A/Brisbane/59/ Naive diss Days post infection

12 Objective 4: Vaccine efficacy in hon-human primates Three groups of monkeys (4 animals each) received 45 μg of the trivalent vaccine by: Hypodermic needle injection () Metal microneedle arrays Polymer microneedle patches Macaca mullatta (rhesus macaque) 2-year old Prime Boost Day Day 7 Day 14 Day 21 Day 28 Week 7 Week 8 Week 9 Week 52 Blood and nasopharyngeal swabs Blood

13 Samples collected Whole blood for CBC and WBC phenotype Serum for humoral responses (binding Abs, HAI, Neutralizing antibodies and plaque reduction assay) Plasma for chemokines/cytokines (Luminex) Whole blood for T cell responses (FACS, ELISPOT assays) and B cell responses (ASC and memory B cells) Nasopharyngeal swabs for mucosal responses (IgA)

14 Anti-B/Brisbane/6/28 HAI titers anti-a/brisbane/9/7 HAI titers boost prime boost prime anti-a/victoria/21/29 HAI titers boost prime All groups showed similar HAI titers against influenza A viruses after boost H1N1 H3N weeks after immunization weeks after immunization B weeks after immunization

15 IgA (nasopharyngeal) O.D. IgA (nasopharyngeal) O.D. IgA (nasopharyngeal) O.D. Mucosal IgA responses were higher in the dissolving microneedle group, with a peak between 14 and 21 days H1N H3N days post-prime days post-prime B days post-prime

16 d d7 d21 d d7 d21 d d7 d21 B/Brisbane/6/8 specific IgGsecreting cells TIV specific memory B cells/ 1 6 PBMC d d7 d21 d d7 d21 d d7 d21 d d7 d21 d d7 d21 d d7 d21 A/Brisbane/59/7 specific IgGsecreting cells A/Victoria/21/9 specific IgG secreting cells Total IgG memory B cells/ 1 6 PBMC Animals immunized with showed higher influenza-specific ASC numbers three weeks after prime and flu specific memory B cells 2 weeks after boost H1N1 H3N B d14 pb

17 wk wk1 wk2 wk3 wk4 wk7 boost prime wk8 wk9 wk52 anti-b/brisbane/6/8 NT titers wk wk1 wk2 wk3 wk4 wk7 wk8 wk9 wk52 wk wk1 wk2 wk3 wk4 wk7 boost prime wk8 wk9 wk52 a-a/brisbane/59/7 NT titers boost prime a-a/victoria/21/9 NT titers Skin vaccination induced similar levels of neutralizing antibody titers against all influenza viruses as the group H1N1: max titers H3N2: max titers B: max titers

18 T cell immune responses were similar among all vaccinated groups: Comparable frequencies of activated CD4+ and CD8+ T CM and T EM cells among all vaccinated cohorts Comparable frequencies of proliferating CD8+ T CM and T EM cells among all vaccinated cohorts The dissolving microneedle group demonstrated more consistent proliferative capacity of CD4 + T EM cells In the dissolving microneedle group we observed higher numbers of IL-4 secreting T cells with a peak 3 weeks after prime Cellular immune responses

19 Although the sample size of this study is too small to draw conclusions the result gives us a hint of what we should expect in clinical trials: diversity of responses and at least noninferiority between technologies More correlates of immunity should be included in vaccine technology development: Systemic humoral responses are not different between intramuscular or skin vaccination but mucosal responses may benefit from skin delivery Skin vaccination may exert quantitative but not qualitative advantages in T cell responses but in vaccines robustness of immune response is critical. Conclusions

20 Phase I clinical trials of dissolving microneedles in 215 Improving immune responses in high risk populations Vaccine stability studies at various temperatures and extended times Novel adjuvants for skin immunization Future plans

21 ACKNOWLEDGMENTS M. P. Prausnitz H.S. Gill V. G. Zarnitsyn S.P. Sullivan J.W. Lee S.O. Choi N. Murthy H. Kalluri D. McAllister W. Pewin C. Edens S. Henry Derek O Hagan Ph.D. Sushma Kommaredy I. Skountzou R.W. Compans E. V. Vassilieva J. A. Pulit-Penaloza C. Ibegbu E. S. Esser M. T. Taherbhai S. Gill D.G. Koutsonanos M. del P. Martin Matos W.C. Weldon A. Stavropoulou Z. Ashraf M. McLausland J. Jacob L. Ye