{"doi":"10.1111/imm.13661","title":"Ability of <scp>SpikoGen</scp>®, an <scp>Advax‐CpG</scp> adjuvanted recombinant spike protein vaccine, to induce cross‐neutralising antibodies against <scp>SARS‐CoV</scp>‐2 variants","abstract":"SpikoGen® vaccine is a subunit COVID-19 vaccine expressed in insect cells comprising recombinant spike protein extracellular domain formulated with Advax-CpG55.2™ adjuvant. A Phase 2 trial was conducted in 400 adult participants randomised 3:1 to receive two intramuscular doses of SpikoGen® vaccine or saline placebo 3 weeks apart. Some Phase 2 trial participants later enrolled in a separate booster study and received a third dose of SpikoGen® vaccine. This stored serum was used to assess the ability of SpikoGen® vaccine to induce cross-neutralising antibodies against SARS-CoV-2 variants of concern. Sera taken at baseline and 2 weeks after the second vaccine dose from baseline seronegative Phase 2 subjects was evaluated using a panel of spike pseudotype lentivirus neutralisation assays for the ability to cross-neutralise a wide range of SARS-CoV-2 variants, including Omicron BA.1, BA.2 and BA.4/5. Stored samples of subjects who participated in both the 2-dose Phase 2 trial and a third dose booster trial 6 months later were also analysed for changes in cross-neutralising antibodies over time and dose. Two weeks after the second dose, sera broadly cross-neutralised most variants of concern, albeit with titres against Omicron variants being ~10-fold lower. While Omicron titres fell to low levels 6 months after the second vaccine dose in most subjects, they showed a ~20-fold rise after the third dose booster, after which there was only a ~2-3-fold difference in neutralisation of Omicron and the ancestral strains. Despite being based on the ancestral Wuhan sequence, after two doses, SpikoGen® vaccine induced broadly cross-neutralising serum antibodies. Titres then reduced over time but were rapidly restored by a third dose booster. This resulted in high neutralisation including against the Omicron variants. This data supports ongoing use of SpikoGen® vaccine for protection against recent SARS-CoV-2 Omicron variants.","journal":"Immunology","year":2023,"id":357832,"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":12,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9564,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1107609,"name":"Anna Antipov","orcid":"0000-0001-6557-7781","position":1,"is_corresponding":false},{"id":1107610,"name":"Greiciely O. André","orcid":"0000-0002-2467-4291","position":2,"is_corresponding":false},{"id":865949,"name":"Saghar Barati","orcid":"0000-0002-5620-338X","position":3,"is_corresponding":false},{"id":1107994,"name":"Hamidreza Kafi","orcid":null,"position":4,"is_corresponding":false},{"id":299291,"name":"Nikolai Petrovsky","orcid":"0000-0002-1580-5245","position":5,"is_corresponding":false},{"id":727286,"name":"Yoshikazu Honda‐Okubo","orcid":"0000-0002-2872-8621","position":0,"is_corresponding":true}],"reference_count":29,"raw_metadata":null,"created_at":"2026-07-19T01:13:39.186262Z","pmid":"37199229","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":[]}