# Safety and immunogenicity of GamEvac-Combi, a heterologous rVSV- and rAd5-vectored Ebola vaccine: a randomized controlled multicenter clinical trial in the Republic of Guinea and Russia **Authors:** Denis Y. Logunov, Inna V. Dolzhikova, Mamadou Y. Boiro, Anna V. Kovyrshina, Alina S. Dzharullaeva, Alina S. Erokhova, Daria M. Grousova, Amir I. Tukhvatulin, Fatima M. Izhaeva, Yana V. Simakova, Maria K. Ordzhonikidze, Nadezhda L. Lubenets, Olga V. Zubkova, Dmitrii V. Scheblyakov, Ilias B. Esmagambetov, Maksim M. Shmarov, Alexander S. Semikhin, Natalia M. Tukhvatulina, Dmitrii N. Shcherbinin, Irina L. Tutykhina, Georgiy S. Prokhorov, Alexander A. Khovaev, Tatiana N. Demidova, Nikolai A. Malishev, Liliya N. Merkulova, Olga L. Voronina, Irina T. Fedyakina, Lidiya B. Kisteneva, Lyudmila V. Kolobukhina, Dmitry V. Mishin, Aleksandr L. Elakov, Ekaterina I. Ermolova, Kirill G. Krasnoslobodtsev, Viktor F. Larichev, Irina S. Kruzhkova, Egor M. Burmistrov, Anna B. Sheremet, Elizaveta A. Tokarskaya, Alexander V. Gromov, Dmitrii A. Reshetnikov, Aleksandr I. Fisun, Bogdan N. Kotiv, Dmitrii V. Ovchinnikov, Evgenii V. Ivchenko, Konstantin V. Zhdanov, Sergei M. Zakharenko, Aleksandr N. Solovev, Andrei M. Ivanov, Vitalii S. Sukachev, Roman V. Gudkov, Oleg V. Maltsev, Ilnur A. Gabdrakhmanov, Anton V. Barsukov, Vladislav V. Vashchenkov, Nikolai I. Demianenko, Sergei B. Ignatev, Konstantin V. Asiamov, Nikolai N. Kirichenko, Andrei V. Liubimov, Igor I. Volkov, Evgenii V. Kriukov, Nikolai K. Bazarnov, Viktoriia A. Kolodiazhnaia, Elena V. Kolomoets, Svetlana I. Syromyatnikova, Dmitry E. Chifanov, Alexander F. Andrus, Dmitry A. Kutaev, Sergei V. Borisevich, Boris S. Naroditsky, Alexander L. Gintsburg PMC · DOI: 10.3389/fimmu.2025.1487039 · 2025-03-20 ## TL;DR A new Ebola vaccine called GamEvac-Combi was tested in a clinical trial and found to be safe and effective at triggering strong immune responses. ## Contribution The study presents a novel heterologous rVSV- and rAd5-vectored Ebola vaccine and evaluates its safety and immunogenicity in a multicenter trial. ## Key findings - The vaccine induced strong cell-mediated and humoral immune responses, with high seroconversion rates. - Neutralizing antibody levels remained elevated for at least one year after vaccination. - The vaccine demonstrated a favorable safety profile over the 12-month observation period. ## Abstract Ebola virus disease (EVD) is one of the most dangerous and lethal diseases affecting humans. There are several licensed vaccines against EVD, but it remains one of the priority diseases for research and development of effective vaccines. A double-blind randomized placebo-controlled trial was performed to evaluate safety and immunogenicity of rVSV- and rAd5-vectored vaccine GamEvac-Combi in healthy adults of both sexes between 18 and 60 years. Safety and immunogenicity were assessed during the observation period of 12 months. Immunogenicity was assessed with GP-specific ELISA, IFN-γ ELISA, and plaque pseudoneutralization assay. Vaccinated participants showed marked GP-specific IFN-γ response at day 28 and neutralizing response at day 42 (GMT = 32.6, seroconversion rate 96.3%). GP-specific IgG antibody levels in vaccinated participants peaked at day 42 (GMT = 9345) and persisted for a year after vaccination (GMT = 650). The vaccine showed favorable safety profile and induced robust cell-mediated immune response and strong humoral immune response that lasts at least for a year from the start of vaccination. ClinicalTrials.gov, identifier NCT03072030; Pan African Clinical Trial Registry, identifier PACTR201702002053400. ## Linked entities - **Proteins:** TNC (tenascin C) - **Diseases:** Ebola virus disease (MONDO:0005737) ## Full-text entities - **Genes:** RNF130 (ring finger protein 130) [NCBI Gene 55819] {aka G1RP, G1RZFP, GOLIATH, GP}, IFNG (interferon gamma) [NCBI Gene 3458] {aka IFG, IFI, IMD69} - **Diseases:** EVD (MESH:D019142) - **Chemicals:** GamEvac (-) - **Species:** Ebola virus (no rank) [taxon 1570291], Homo sapiens (human, species) [taxon 9606] ## Figures 4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC11979634/full.md --- Source: https://tomesphere.com/paper/PMC11979634