{"doi":"10.1101/2020.11.04.367359","title":"SARS-CoV-2 RBD219-N1C1: A Yeast-Expressed SARS-CoV-2 Recombinant Receptor-Binding Domain Candidate Vaccine Stimulates Virus Neutralizing Antibodies and T-cell Immunity in Mice","abstract":"Abstract There is an urgent need for an accessible and low-cost COVID-19 vaccine suitable for low- and middle-income countries. Here we report on the development of a SARS-CoV-2 receptor-binding domain (RBD) protein, expressed at high levels in yeast ( Pichia pastoris ), as a suitable vaccine candidate against COVID-19. After introducing two modifications into the wild-type RBD gene to reduce yeast-derived hyperglycosylation and improve stability during protein expression, we show that the recombinant protein, RBD219-N1C1, is equivalent to the wild-type RBD recombinant protein (RBD219-WT) in an in vitro ACE-2 binding assay. Immunogenicity studies of RBD219-N1C1 and RBD219-WT proteins formulated with Alhydrogel ® were conducted in mice, and, after two doses, both the RBD219-WT and RBD219-N1C1 vaccines induced high levels of binding IgG antibodies. Using a SARS-CoV-2 pseudovirus, we further showed that sera obtained after a two-dose immunization schedule of the vaccines were sufficient to elicit strong neutralizing antibody titers in the 1:1,000 to 1:10,000 range, for both antigens tested. The vaccines induced IFN-γ, IL-6, and IL-10 secretion, among other cytokines. Overall, these data suggest that the RBD219-N1C1 recombinant protein, produced in yeast, is suitable for further evaluation as a human COVID-19 vaccine, in particular, in an Alhydrogel ® containing formulation and possibly in combination with other immunostimulants.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2020,"id":119168,"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":26,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9544,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":277588,"name":"Wen‐Hsiang Chen","orcid":"0000-0002-0542-1598","position":1,"is_corresponding":false},{"id":378359,"name":"Leroy Versteeg","orcid":"0000-0001-5250-5746","position":2,"is_corresponding":false},{"id":378361,"name":"Brian Keegan","orcid":"0000-0001-9140-8690","position":3,"is_corresponding":false},{"id":342530,"name":"Bin Zhan","orcid":"0000-0002-6884-9452","position":4,"is_corresponding":false},{"id":553628,"name":"Junfei Wei","orcid":"0000-0002-0041-5535","position":5,"is_corresponding":false},{"id":342528,"name":"Zhuyun Liu","orcid":"0000-0002-6672-1383","position":6,"is_corresponding":false},{"id":290373,"name":"Jungsoon Lee","orcid":null,"position":7,"is_corresponding":false},{"id":554854,"name":"Rahki Kundu","orcid":null,"position":8,"is_corresponding":false},{"id":553629,"name":"Rakesh Adhikari","orcid":"0000-0003-0829-232X","position":9,"is_corresponding":false},{"id":553630,"name":"Cristina Poveda","orcid":"0000-0003-0361-2232","position":10,"is_corresponding":false},{"id":553631,"name":"María José Villar","orcid":"0000-0002-2939-1928","position":11,"is_corresponding":false},{"id":554855,"name":"Ana Carolina de Araújo Leão","orcid":null,"position":12,"is_corresponding":false},{"id":554856,"name":"Joanne Altieri Rivera","orcid":null,"position":13,"is_corresponding":false},{"id":279018,"name":"Zoha Momin","orcid":"0000-0002-2247-7665","position":14,"is_corresponding":false},{"id":553632,"name":"Portia M. Gillespie","orcid":"0000-0003-2951-4550","position":15,"is_corresponding":false},{"id":279021,"name":"Jason T. Kimata","orcid":"0000-0002-0504-0090","position":16,"is_corresponding":false},{"id":231474,"name":"Ulrich Strych","orcid":"0000-0001-9455-7683","position":17,"is_corresponding":false},{"id":42798,"name":"Peter J. Hotez","orcid":"0000-0001-8770-1042","position":18,"is_corresponding":false},{"id":231472,"name":"María Elena Bottazzi","orcid":"0000-0002-8429-0476","position":19,"is_corresponding":false},{"id":277590,"name":"Jeroen Pollet","orcid":"0000-0003-1420-4015","position":0,"is_corresponding":true}],"reference_count":46,"raw_metadata":null,"created_at":"2026-07-18T23:14:08.313144Z","pmid":"33173864","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":[]}