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oai:repisalud.isciii.es:20.500.12105/154542025-04-01T08:11:46Zcom_20.500.12105_2052com_20.500.12105_2051com_20.500.12105_15322col_20.500.12105_19609col_20.500.12105_16938col_20.500.12105_16963col_20.500.12105_16969col_20.500.12105_16976col_20.500.12105_16987

00925njm 22002777a 4500 dc García-Pérez, Javier author Gonzalez-Perez, Maria author Castillo de la Osa, María author Borobia, Alberto M author Castaño, Luis author Bertrán, María Jesús author Campins, Magdalena author Portolés, Antonio author Lora, David author Bermejo, Mercedes author Conde-San Román, Patricia author Hernandez, Lourdes author Carcas, Antonio author Arana-Arri, Eunate author Tortajada, Marta author Fuentes, Inmaculada author Ascaso, Ana author García-Morales, María Teresa author de la Torre-Tarazona, Humberto Erick author Arribas, José Ramón author Imaz-Ayo, Natale author Mellado-Pau, Eugènia author Agustí, Antonia author Pérez-Ingidua, Carla author Gómez de la Cámara, Agustín author Ochando, Jordi author Belda-Iniesta, Cristobal author Frías, Jesús author Alcamí, José author Perez-Olmeda, Mayte author CombiVacS Study Group author 2022-07-01 Background: The CombiVacS study was designed to assess immunogenicity and reactogenicity of the heterologous ChAdOx1-S/BNT162b2 combination, and 14-day results showed a strong immune response. The present secondary analysis addresses the evolution of humoral and cellular response up to day 180. Methods: Between April 24 and 30, 2021, 676 adults primed with ChAdOx1-S were enrolled in five hospitals in Spain, and randomised to receive BNT162b2 as second dose (interventional group [IG]) or no vaccine (control group [CG]). Individuals from CG received BNT162b2 as second dose and also on day 28, as planned based on favourable results on day 14. Humoral immunogenicity, measured by immunoassay for SARS-CoV-2 receptor binding domain (RBD), antibody functionality using pseudovirus neutralisation assays for the reference (G614), Alpha, Beta, Delta, and Omicron variants, as well as cellular immune response using interferon-γ and IL-2 immunoassays were assessed at day 28 after BNT162b2 in both groups, at day 90 (planned only in the interventional group) and at day 180 (laboratory data cut-off on Nov 19, 2021). This study was registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739). Findings: In this secondary analysis, 664 individuals (441 from IG and 223 from CG) were included. At day 28 post vaccine, geometric mean titres (GMT) of RBD antibodies were 5616·91 BAU/mL (95% CI 5296·49-5956·71) in the IG and 7298·22 BAU/mL (6739·41-7903·37) in the CG (p < 0·0001). RBD antibodies titres decreased at day 180 (1142·0 BAU/mL [1048·69-1243·62] and 1836·4 BAU/mL [1621·62-2079·62] in the IG and CG, respectively; p < 0·0001). Neutralising antibodies also waned from day 28 to day 180 in both the IG (1429·01 [1220·37-1673·33] and 198·72 [161·54-244·47], respectively) and the CG (1503·28 [1210·71-1866·54] and 295·57 [209·84-416·33], respectively). The lowest variant-specific response was observed against Omicron-and Beta variants, with low proportion of individuals exhibiting specific neutralising antibody titres (NT50) >1:100 at day 180 (19% and 22%, respectively). Interpretation: Titres of RBD antibodies decay over time, similar to homologous regimes. Our findings suggested that delaying administration of the second dose did not have a detrimental effect after vaccination and may have improved the response obtained. Lower neutralisation was observed against Omicron and Beta variants at day 180. eClinicalMedicine. 2022 Jul 1;50:101529. 10.1016/j.eclinm.2022.101529 2589-5370 EClinicalMedicine 35795713 http://hdl.handle.net/20.500.12105/15454 SARS-CoV-2 Heterologous vaccination Neutralisation Variants Antibodies Immunogenic dynamics and SARS-CoV-2 variant neutralisation of the heterologous ChAdOx1-S/BNT162b2 vaccination: Secondary analysis of the randomised CombiVacS study