{"doi":"10.1101/2023.08.07.552330","title":"NVX-CoV2373 ancestral and NVX-CoV2540 BA.5 protein nanoparticle vaccines protect against Omicron BA.5 variant in Syrian hamsters","abstract":"SUMMARY The emergence of SARS-CoV-2 variants with greater transmissibility or immune evasion properties has jeopardized the existing vaccine and antibody-based countermeasures. Here, we evaluated the efficacy of boosting with the protein nanoparticle NVX-CoV2373 or NVX-CoV2540 vaccines containing ancestral or BA.5 S proteins, respectively, in mRNA-immunized pre-immune hamsters, against challenge with the Omicron BA.5 variant of SARS-CoV-2. Serum antibody binding and neutralization titers were quantified before challenge, and viral loads were measured 3 days after challenge. Compared to an mRNA vaccine boost, NVX-CoV2373 or NVX-CoV2540 induced higher serum antibody binding responses against ancestral Wuhan-1 or BA.5 spike proteins, and greater neutralization of Omicron BA.1 and BA.5 variants. One and three months after vaccine boosting, hamsters were challenged with the Omicron BA.5 variant. NVX-CoV2373 and NVX-CoV2540 boosted hamsters showed reduced viral infection in the nasal washes, nasal turbinates, and lungs compared to unvaccinated animals. Also, NVX-CoV2540 BA.5 boosted animals had fewer breakthrough infections than NVX-CoV2373 or mRNA-vaccinated hamsters. Thus, immunity induced by NVX-CoV2373 or NVX-CoV2540 boosting can protect against the Omicron BA.5 variant in the Syrian hamster model. IMPORTANCE As SARS-CoV-2 variants continue to emergence, the efficacy of prior and updated COVID-19 vaccines need to be tested. Here, we tested the efficacy of two nanoparticle protein-based vaccines in pre-immune hamsters against a challenge with the BA.5 Omicron variant of SARS-CoV-2. Compared to an mRNA vaccine boost, the nanoparticle vaccine NVX-CoV2373 and NVX-CoV2540 induced higher serum antibody binding and neutralization responses against ancestral Wuhan-1 or BA.5 variants. One and three months after the last immunization, hamsters were challenged with the Omicron BA.5 variant. NVX-CoV2373 and NVX-CoV2540 boosted hamsters showed reduced viral infection in the nasal washes, nasal turbinates, and lungs compared to unvaccinated animals. Animals that received the homologous vaccine, NVX-CoV2540, had fewer breakthrough infections than NVX-CoV2373 or mRNA-vaccinated hamsters. Together, our data shows that the BA.5 nanoparticle vaccine is effective and that it is important to update the COVID-19 vaccine to match currently circulating strains of SARS-CoV-2.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2023,"id":400372,"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":0.9555,"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":252252,"name":"Astha Joshi","orcid":"0000-0003-4914-8228","position":1,"is_corresponding":false},{"id":1161212,"name":"Nadia Soudani","orcid":"0000-0002-0191-7860","position":2,"is_corresponding":false},{"id":689736,"name":"Suzanne M. Scheaffer","orcid":"0009-0001-0459-0816","position":3,"is_corresponding":false},{"id":230745,"name":"Nita Patel","orcid":"0000-0003-4976-061X","position":4,"is_corresponding":false},{"id":1177276,"name":"Mimi Guebre-Xabier","orcid":null,"position":5,"is_corresponding":false},{"id":230748,"name":"Gale Smith","orcid":"0000-0002-6482-6026","position":6,"is_corresponding":false},{"id":106529,"name":"Michael Diamond","orcid":"0000-0002-8791-3165","position":7,"is_corresponding":false},{"id":334926,"name":"Adrianus C. M. Boon","orcid":"0000-0002-4700-8224","position":8,"is_corresponding":false},{"id":553176,"name":"Traci L. Bricker","orcid":null,"position":0,"is_corresponding":true}],"reference_count":29,"raw_metadata":null,"created_at":"2026-07-19T01:20:04.010538Z","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":[]}