Transgene Sa · EURONEXT:TNG
Transgene Sa — World Congress on Infectious Diseases 2026
30 slides from Transgene Sa's conference presentation, Jun 25, 2026
Slide 1: Robust Protection Against Monkeypox Virus Mediated By a Novel Cell-Line-Derived MVA Vaccine (TG-MVACL)
Robust Protection Against Monkeypox Virus Mediated By a Novel Cell-Line-Derived MVA Vaccine (TG-MVACL) Nathalie Silvestre, Head of the Vectorology Laboratory at Transgene World Congress on Infectious Diseases 25 June 2026 1
Slide 2: Disclaimer
Disclaimer Data presented herein reflect preclinical analyses available as of the date of this presentation. These results are preliminary and intended for scientific discussion only. They are not predictive of future outcomes and should not be construed as a guarantee of the results, safety, or eff
Slide 3: Outline
OUTLINE • Background • TG-MVA : a proposed third generation vaccine for mpox and smallpox produced on cell line • TG-MVA : immunogenicity and efficacy in animal models 3
Slide 4: Monkeypox Virus (MPXV)
Monkeypox Virus (MPXV) An orthopoxvirus belonging to the same family as the Variola virus causing smallpox • General features • Large complex enveloped virions (360 x 250 x 200 nm) belonging to the Poxviridae family • Member of the orthopoxvirus genus, which includes vaccinia virus (VACV) and variol
Slide 5: Monkeypox (mpox): a New Threat
Monkeypox (mpox) : a New Threat Increase of global burden since 2022 Before 2022 • Mpox was an emerging disease circulating in limited regions in Africa with sporadic cases out of the continent • May: Outbreak caused by Clade IIb in Africa and in non endemic country (UK) and fast spread to EU and US
Slide 6: Orthopox-Related Diseases: a Global Threat
Orthopox-Related Diseases : a Global Threat • Mpox: a convergence of viral evolution, ecological changes, human behavior, and public health limitations • Increased risk of health emergency due to climate change, emerging and engineered pathogens, global mobility, and geopolitical instability • Emerg
Slide 7: Vaccines Against Smallpox and Mpox
Vaccines Against Smallpox and Mpox Licensed second & third-generation smallpox / mpox vaccines • Vaccines used during the smallpox eradication campaign based on live vaccinia virus (replication-competent) First • Produced directly on the skin of live animals (e.g: Dryvax®) generation • Highly effect
Slide 8: MVA (Modified Vaccinia Ankara): a Potent Smallpox and Mpox Vaccine
MVA (Modified Vaccinia Ankara) : a Potent Smallpox and Mpox Vaccine • MVA was obtained from the CVA1 vaccinia virus isolate by Pr. A. Mayr in late 70's after 572 passages onto chicken embryo fibroblasts (CEF) • Lost over 15% of the viral genome (6 major deletions), including host range restriction g
Slide 9: Orthopox-Related Threats: a Strategic Preparedness Challenge
Orthopox-Related Threats : a Strategic Preparedness Challenge • Challenge as vaccine supply is fragile • Current system depends on too few suppliers • Single supplier (monopoly) for MVA vaccine (Bavarian Nordic) with limited capacity and centralized production • Europe relies on a single approved mp
Slide 10: TG-MVA | Building Next Line of Biosecurity Against Pox-Diseases
TG-MVA | Building Next Line of Biosecurity Against Pox-Diseases • TG-MVA : A Safe Third-Generation Vaccine • Non-replicating pox vaccine built on a viral backbone identical to Bavarian Nordic’s reference platform: shared MVA lineage (100% Region of Interest (ROI) sequence identity) • Designed to pro
Slide 11: TG-MVA | Pre-Clinical Studies
TG-MVA | Pre-Clinical Studies Generated non-clinical evidence of TG-MVA efficacy, immunogenicity & safety Objective: to compare the efficacy, immunogenicity & safety of TG-MVA and MVA-BN® in established Non-human primates and murine animal models Immunogenicity study mpox lethal-challenge mpox letha
Slide 12: Immunogenicity in BALB/c Mice: Study Design
Immunogenicity in BALB/c Mice: Study Design • Tested items • MVA-BN® (Jynneos®) : registered as a prophylactic vaccine against Mpox and smallpox, produced on CEF • TG-MVACEF (TG4080) : TG-MVA produced on CEF • TG-MVACL (TG4090) : TG-MVA produced on avian cell line • Vehicule: formulation buffer Obje
Slide 13: Immunogenicity in BALB/c Mice: Antibodies Response
Immunogenicity in BALB/c Mice: Antibodies Response TG-MVA induce Total and Neutralizing VACV Ab comparable to MVA-BN® Total Ab detected at D42/D43 Neutralizing Ab detected at D42/D43 LOD *** *** LOD *** *** *** *** *** p<0.001, **p<0.01, * p<0.05 Total Anti-VAVC titers expressed as IC50 for individu
Slide 14: Immunogenicity in BALB/c Mice: Cellular Response Assessed by ELISpot
Immunogenicity in BALB/c Mice : Cellular Response Assessed by ELISpot TG-MVA and MVA-BN® induce similar cellular immune response Stimulation : Not infected P815 cells : P815 cells infected with VACV strain Western Reserve : mix of 3 specific MVA peptides : mix of 3 specific WR peptides Detection of
Slide 15: Mpox Lethal-Challenge Study in CAST/Ei Mice: Study Design
Mpox Lethal-Challenge Study in CAST/Ei Mice: Study Design Objective: Demonstrate that TG-MVA and MVA-BN® have similar immunogenicity and that change of manufacturing process has no impact on immunotoxic potential compared to manufacturing on CEF ➢ CAST/Ei mice* is a strain of mice for which MPXV cha
Slide 16: Mpox Lethal-Challenge Study in CAST/Ei Mice: Survival and Weight Loss
Mpox Lethal-Challenge Study in CAST/Ei Mice : Survival and Weight Loss TG-MVA and MVA-BN® provide equivalent protection against MPXV challenge Survival Weight loss ➢ No lethality in all MVA-vaccinated group ➢ Minor weight loss in MVA-vaccinated mice 16
Slide 17: TG-MVA | Conclusions in Mice Models
TG-MVA | Conclusions in Mice Models • Primary end-point: Protection is reached (CAST/Ei mice) for all three MVAs and with identical efficacy (100% for all groups) • Secondary end-points: Morbidity/Immunogenicity o Weight Loss : minimal and same weight loss for the three MVA vaccines groups o MPXV ne
Slide 18: Mpox Lethal-Challenge Study in NHP: Study Design
Mpox Lethal-Challenge Study in NHP: Study Design A gold-standard for anti-Mpox vaccine evaluation Objective: Demonstrate that TG-MVA and MVA-BN® have similar immunogenicity and that change of manufacturing process has no impact on immunotoxic potential compared to manufacturing on CEF NHP Vehicle MP
Slide 19: Mpox Lethal-Challenge Study in NHP: Survival and Weight Loss
Mpox Lethal-Challenge Study in NHP : Survival and Weight Loss TG-MVA and MVA-BN® provide equivalent protection against MPXV challenge : MVA-BN® : TG-MVA_CEF : MVA-BN® : TG-MVA_CEF (Log-rank p=0.0001) : TG-MVA_CL : TG-MVA_CL ➢ 7/8 animals survived in all MVA-vaccinated group ➢ Minor weight loss in MV
Slide 20: Mpox Lethal-Challenge Study in NHP: Lesion Counts
Mpox Lethal-Challenge Study in NHP: Lesion Counts TG-MVA and MVA-BN® strongly protect against MPXV-induced lesion development : MVA-BN® Number of animal : TG-MVA_CEF With lesions* Without lesions : TG-MVA_CL MVA-BN® 7 (87,5%) 1(12,5%) TG-MVACEF 8 (100.0%) 0 (0%) TG-MVACL 5 (62.5%) 3 (37.5%) Vehicle
Slide 21: NHP: Neutralizing anti-VACV Ab
Mpox Lethal-Challenge Study in NHP: Neutralizing anti-VACV Ab TG-MVA and MVA-BN® provide similar immunogenicity against VACV MPXV Challenge Anti-VAVC neutralization titers expressed as NT50. Data represents geometric mean for each group. ➢ Prior to challenge, peak of response at D42 ➢ Comparable Tit
Slide 22: NHP: Neutralizing anti-MPXV
Mpox Lethal-Challenge Study in NHP: Neutralizing anti-MPXV TG-MVA and MVA-BN® provide similar immunogenicity against MPXV a Anti-MPXV neutralization titers expressed as NT50. Data represents geometric mean for each group. • Prior to challenge, peak of response at D42 • Prior to challenge, peak of re
Slide 23: NHP: Total Antibodies Against VACV Proteins
Mpox Lethal-Challenge Study in NHP: Total Antibodies Against VACV Proteins* TG-MVA and MVA-BN® provide similar immunogenicity against VACV proteins * : Orthologous late proteins from IMV and EEV viral particle known to be associated with protection Mean of log concentration of VACV protein-binding I
Slide 24: NHP: Total Antibodies Against MPXV Proteins
Mpox Lethal-Challenge Study in NHP : Total Antibodies Against MPXV Proteins* TG-MVA and MVA-BN® provide similar immunogenicity against MPXV proteins * : Orthologous late proteins from IMV and EEV viral particle known to be associated with protection Mean of log concentration of MPXV protein-binding
Slide 25: NHP: Cellular Response Assessed by ELISpot
Mpox Lethal-Challenge Study in NHP: Cellular Response Assessed by ELISpot TG-MVA and MVA-BN® induce similar cellular immune response Stimulation: PepMix Pan-Poxviridae Select 127 peptides class I & II restricted T-cells epitopes) - 122 found in MPXV - 126 found in VACV WR Detection of IFN-gamma prod
Slide 26: NHP: Viremia in Blood and Throat Swab
Mpox Lethal-Challenge Study in NHP: Viremia in Blood and Throat Swab TG-MVA and MVA-BN® provide markedly attenuated systemic viral burden Log10 MPXV genome copy numbers. Data represents mean +/-SEM Log10 MPXV genome copy numbers. Data represents mean +/-SEM TG-MVA_CL : Only 1 positive NHP from J18 •
Slide 27: Safety Assessment
Safety Assessment Similar safety profile among all three vaccines Safety end-points were incorporated in the NHP efficacy study : • Hematology/biochemistry : • Variations observed after MPXV exposure consistent with viral infection (increased WBC, slight increased of liver enzymes and globulin conce
Slide 28: TG-MVA | Conclusions
TG-MVA | Conclusions • TG-MVACEF and TG-MVACL demonstrate efficacy, immunogenicity and safety comparable to MVA-BN® • Protection for severe mpox morbidity and mortality • Induction of comparable level of Neutralizing anti-VACV antibody • Comparable peak viremia levels observed in blood and throat sw
Slide 29: Acknowledgments
Acknowledgments Jean-Baptiste Marchand Kar Swagata Patricia Kleinpeter Bhavna Chawla Véronique Koerper Christelle Remy Hakim Makhloufi Bérangère Marie-Bastien Clémentine Spring-Giusti Geneviève Inchauspé Emmanuelle Dochy Maurizio Ceppi Laurence Laruelle Sarkar Sanjay Martine Marigliano Jessica Marti
Slide 30: Thank you for your attention
Thank you for your attention 30
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