Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases
Aurélie Wiedemann, Édouard Lhomme, Mélanie Huchon, Emile Foucat, Marion Bérerd-Camara, Lydia Guillaumat, Marcel Yaradouno, Jacqueline Tambalou, Cécile Rodrigues, Alexandre Lima de Araújo Ribeiro, Abdoul Habib Béavogui, Christine Lacabaratz, Rodolphe Thiébaut, Laura Richert, Yves Lévy, the Prevac study team, Jamila Aboulhab, Michelle Aguirre-MacKenzie, Pauline Akoo, Esther Akpa, Robert Akpata, Sara Albert, Boni Maxime Ale, Serry Alimamy-Bangura, Pierre Andong, Benetta C. Andrews, Stephane Anoma, Negin Atri, Augustin Augier, Ken Awuondo, Ahidjo Ayouba, Moses Badio, Aminata Bagayoko, Abby Balde, Joséphine Balssa, Lamin Molecule Bangura, Kesha Barrington, Eric Barte de Saint Fare, Beth Baseler, Ali Bauder, Claire Bauduin, Luke Bawo, Abdoul Habib Béavogui, Michael Belson, Safaa Ben-Farhat, Marion Bererd, Nicolas Bernaud, Teedoh Beyslow, Neirade Biai, Jeanne Billioux, Shere Billouin-Frazier, Blandine Binachon, Julie Blie, Viki Bockstal, Patricia Boison, Fatorma K. Bolay, Aliou Boly, Rachael Bonawitz, Anne-Gaëlle Borg, Samuel Bosompem, Courtney Bozman, Tyler Brady, Sarah Browne, Ryan Bullis, Barbara Cagniard, Kelly Cahill, Yíngyún Caì, Aissata Abdoulaye Camara, Aboubacar Keira Camara, Alseny Camara, Antoine Campagne, Cécilia Campion, Alexandre Cantan, Jennifer Cash, Siew Pin Chai, Francois Chambelin, Michael Chea, Geneviève Chêne, Edouard Choi, Michelle Chouinard, Florence Chung, Lucy Chung, Séverine Ciancia, Papa Ndiaga Cissé, Elfrida Cline-Cole, Céline Colin, Beth-Ann Coller, Djélikan Siaka Conde, Katherine Cone, Laurie Connor, Nicholas E. Connor, Joseph B. Cooper, Sandrine Couffin-Cardiergues, Fatoumata Coulibaly, Mariam Coulibaly, Page Crew, Tienhan Sandrine Dabakuyo‐Yonli, Djénéba Dabitao, Thierry Damerval, Bionca Davis
Abstract
Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination. In this immunological ancillary study of the PREVAC trial, the authors show that approved Ebola virus vaccines induce memory T-cell responses that persist during the five year follow-up after initial vaccination.