{"doi":"10.1101/2021.08.18.456891","title":"Neutralising antibodies against the SARS-CoV-2 Delta variant induced by Alhydroxyquim-II-adjuvanted trimeric spike antigens","abstract":"ABSTRACT Global control of COVID-19 will require the deployment of vaccines capable of inducing long-term protective immunity against SARS-CoV-2 variants. In this report, we describe an adjuvanted subunit candidate vaccine that affords elevated, sustained and cross-variant SARS-CoV-2 neutralising antibodies (NAbs) in multiple animal models. Alhydroxiquim-II is a TLR7/8 small-molecule agonist chemisorbed on aluminium hydroxide. Vaccination with Alhydroxiquim-II combined with a stabilized, trimeric form of the SARS-CoV-2 spike protein (termed CoVac-II) resulted in high-titre NAbs in mice, with no decay in responses over an 8-month period. NAbs from sera of CoVac-II-immunized mice, horses and rabbits were broadly neutralising against SARS-CoV-2 variants. Boosting long-term CoVac-II-immunized mice with adjuvanted spike protein from the Beta variant markedly increased levels of NAb titres against multiple SARS-CoV-2 variants; notably high titres against the Delta variant were observed. These data strongly support the clinical assessment of Alhydroxiquim-II-adjuvanted spike proteins to protect against SARS-CoV-2 variants of concern.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":221434,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9604,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":653278,"name":"Paco Pino","orcid":"0000-0001-9705-1389","position":1,"is_corresponding":false},{"id":566006,"name":"Alberto Ospina Stella","orcid":"0000-0002-0972-8693","position":2,"is_corresponding":false},{"id":350157,"name":"Caroline L. Ashley","orcid":"0000-0001-8355-8891","position":3,"is_corresponding":false},{"id":821998,"name":"Hannah Lukeman","orcid":null,"position":4,"is_corresponding":false},{"id":299287,"name":"Nayan D. Bhattacharyya","orcid":"0000-0003-4740-6115","position":5,"is_corresponding":false},{"id":16988,"name":"Takuya Tada","orcid":"0000-0003-0779-9954","position":6,"is_corresponding":false},{"id":821999,"name":"Stéphanie Anchisi","orcid":null,"position":7,"is_corresponding":false},{"id":822000,"name":"Charles Metayer","orcid":null,"position":8,"is_corresponding":false},{"id":822001,"name":"Jacopo Martinis","orcid":null,"position":9,"is_corresponding":false},{"id":566009,"name":"Anupriya Aggarwal","orcid":"0000-0001-8678-0519","position":10,"is_corresponding":false},{"id":292174,"name":"Belinda M. Dcosta","orcid":"0000-0001-8497-4942","position":11,"is_corresponding":false},{"id":654237,"name":"Joeri Kint","orcid":null,"position":12,"is_corresponding":false},{"id":822002,"name":"Maria J Wurm","orcid":null,"position":13,"is_corresponding":false},{"id":16989,"name":"Nathaniel R. Landau","orcid":"0000-0002-9997-1004","position":14,"is_corresponding":false},{"id":350158,"name":"Megan Steain","orcid":"0000-0002-7631-4204","position":15,"is_corresponding":false},{"id":566015,"name":"Stuart Turville","orcid":"0000-0003-1918-5343","position":16,"is_corresponding":false},{"id":806327,"name":"Florian Μ. Wurm","orcid":"0000-0003-1114-4520","position":17,"is_corresponding":false},{"id":568886,"name":"Sunil A. David","orcid":"0000-0003-1655-4641","position":18,"is_corresponding":false},{"id":299293,"name":"James A. Triccas","orcid":"0000-0003-3730-2339","position":19,"is_corresponding":false},{"id":299284,"name":"Claudio Counoupas","orcid":"0000-0002-0283-4004","position":0,"is_corresponding":true}],"reference_count":23,"raw_metadata":null,"created_at":"2026-07-18T23:53:55.215284Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}