Presentation on theme: "Pre-clinical Development of a Nasal Adenovirus-Based Vaccine Against Ebola Virus (CRTI 06-0218RD) Public Security S&T Symposium 2009."— Presentation transcript:
Pre-clinical Development of a Nasal Adenovirus-Based Vaccine Against Ebola Virus (CRTI RD) Public Security S&T Symposium 2009
PROJECT BACKGROUND An ongoing NIH sponsored phase 1 clinical trial is evaluating Adenovirus-based vaccine to stimulate significant immune responses against Ebola virus. Goal: Pre-clinical development of a nasal adenovirus-based vaccine against Ebola virus. We have developed an optimized adenovirus-based Ebola vaccine that can stimulate both mucosal and systemic immune responses following nasal immunization. The first objective is to develop a formulated pre-clinical grade optimized AdHu5 EBOV vaccine. The second objective is to advance the knowledge on immune correlates of protection against EBOV in NHPs.
Different Vaccine Strategies –DNA – Vaccinia – VEE replicon – VLPs (Warfield et al. 2007) –HPIV3 – VSV – Adenovirus Have successfully protected NHP (Bukreyev et al., 2007) (Jones et al., 2005) (Sullivan et al., 2000)
Objective To optimize expression of the ZEBOV glycoprotein from an adenoviral vector and compare it to the CMV driven EboGP Ad vaccine vector. Improving the expression cassette Codon optimization Improved CAG promoter
FIX MMI: Computer control Image created by Robert Voyer, BRI-ACTDSP, JAN. 1998
Survival and weight loss 28 days post- vaccination VaccineConcentration (IFU/Mouse) Survival (Percentage) Weight Loss (Percentage) Ad-CMVZGP1 x Ad-CMVZGP1 x Ad-CMVZGP1 x Ad-CAGoptZGP1 x Ad-CAGoptZGP1 x Ad-CAGoptZGP1 x Controlna 1 0>25 Mice were challenged with a lethal dose (LD50 = 1000) of mouse-adapted ZEBOV
Survival of mice 30 min post challenge
Percentage weight loss in post-exposure treatment
Immune response 6 days post- vaccination
Formulations Tested 1Saline, vehicle control (pH 7.4) 2 Ad-ZGP in PBS (pH 7.4) 3Ad-ZGP + Base formulation (Sucrose (10mg/ml), Mannitol (40mg/ml) and Pluronic F68 (0.001%)) 4Ad-ZGP + Base formulation + Selenium (1ug/ml) 5Ad-ZGP + Base formulation + beta-cyclodextrin (0.5%) 6Ad-ZGP + tertiary amine beta-cyclodextrin (5%) 7Ad-ZGP + chitosan (1%) 8Ad-ZGP + Base formulation + chitosan (1%) 9PEGylated Ad-ZGP in PBS (pH 7.4) 10PEGylated Ad-ZGP + Base formulation
Effect of Formulation on Transduction of Calu-3 cells
Frequency of IFN Positive Cells 10 Days After Vaccination (ELISPOT)
Neutralizing Antibody Levels Against Zaire Ebola GP 16 Days After Vaccination
Survival Upon Challenge with Mouse Adapted Ebola Promising Preparations Unsuccessful Preparations
PROJECT STATUS AND ACCOMPLISHMENTS Significant progress steps related to milestones – Comparative evaluation of the first and second generation Ad-Ebo vaccines in mice and guinea pigs. Key Technical Accomplishments, Innovations, Inventions – 100-fold improvement in protective dose, post- exposure protection and overcoming pre-existing immunity. Potential linkages to projects not defined in the Project Charter. –Gene optimization may be beneficial to other vaccine platform such as VSV.
PROJECT SUMMARY AND CONCLUSIONS The optimized vaccine also fully protected mice against a lethal challenge with ZEBOV at a dose 100 times lower than the minimal dose required to achieve full protection with the first generation vaccine. Complete survival was also achieved 30 minutes post-exposure although weight loss was observed. Higher number of IFN-γ, TNF-α and IL-2 positive CD8 T cells and NAB were detected from splenocytes of Ad-CAGoptZGP immunized mice 6 days post-vaccination when compared to AdCMVZGP immunized mice. Several promising formulations have been identified. Mice vaccinated by the nasal route with these preparations have similar or slightly improved immune responses against Ebola and can survive challenge. Published in: PLoS ONE, 2009;4(4):e5308. Epub 2009 Apr 23.
PROJECT REVIEW COMMITTEE Core Members: Project Champion:Dr. Harvey Artsob Project Manager:Dr. Gary Kobinger Portfolio Manager:Norm Yanofsky NRC Management Representative: Dr. Amine Kamen University of Texas Management Representative: Dr. Maria Croyle Associate Members: Procurement Lead: Daniele Cole / Doris Bruneau Deputy Project Manager: Dr. Jim Strong Recording Secretary: Doris Bruneau
Routes of immunization: protection in mice against 200 LD50 of MA-Ebola virus Intramuscular (I.M.) (%) Intranasal (I.N.) (%) Oral (%) Vehicle000 AdHu5-ZGP AdHu5-ZGP + human Ig