{"doi":"10.21203/rs.3.rs-787293/v2","title":"Immune responses following the first dose of the Sputnik V (Gam-COVID-Vac)","abstract":"Abstract As the first dose of Gam-COVID-Vac, is currently used as a single dose vaccine in some countries, we investigated the immunogenicity of this at 4 weeks (327 naïve individuals). 88.7% seroconverted, with significantly lower seroconversion rates in those over 60 years (p = 0.004) and significantly lower than previously seen with AZD1222 (p = 0.018). 82.6% developed ACE2 receptor blocking antibodies, although levels were significantly lower than following natural infection (p = 0.0009) and a single dose of AZD1222 (p < 0.0001). Similar titres of antibodies were observed to the receptor binding domain of WT, B.1.1.7 and B.1.617.2 compared to AZD1222, while the levels for B.1.351 were significantly higher (p = 0.006) for Gam-COVID-Vac. 30% developed ex vivo IFNγ ELISpot responses (significantly lower than AZD1222), and high frequency of CD107a expressing T cells along with memory B cell responses. Although single dose of Gam-COVID-Vac was highly immunogenic, administration of a second dose is likely to be beneficial.","journal":"Research Square","year":2021,"id":218196,"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":3,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9536,"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":778393,"name":"Chandima Jeewandara","orcid":"0000-0001-6830-5175","position":1,"is_corresponding":false},{"id":816017,"name":"Harsha Fernando","orcid":null,"position":2,"is_corresponding":false},{"id":804528,"name":"Pradeep Darshana Pushpakumara","orcid":"0000-0002-4492-6695","position":3,"is_corresponding":false},{"id":805053,"name":"Shyrar Tanussiya","orcid":null,"position":4,"is_corresponding":false},{"id":804529,"name":"Achala Kamaladasa","orcid":"0000-0002-7179-1802","position":5,"is_corresponding":false},{"id":816018,"name":"Banuri Gunasekara","orcid":null,"position":6,"is_corresponding":false},{"id":804527,"name":"Inoka Sepali Aberathna","orcid":"0000-0003-3365-2139","position":7,"is_corresponding":false},{"id":804530,"name":"Heshan Kuruppu","orcid":"0009-0005-8745-8202","position":8,"is_corresponding":false},{"id":804531,"name":"Thushali Ranasinghe","orcid":"0009-0007-4408-9034","position":9,"is_corresponding":false},{"id":805054,"name":"Shashika Dayarathne","orcid":null,"position":10,"is_corresponding":false},{"id":816019,"name":"Osanda Dissanayaka","orcid":null,"position":11,"is_corresponding":false},{"id":805055,"name":"Nayanathara Gamalath","orcid":null,"position":12,"is_corresponding":false},{"id":816020,"name":"Dinithi Ekanayaka","orcid":null,"position":13,"is_corresponding":false},{"id":804532,"name":"Jeewantha Jayamali","orcid":"0000-0001-9919-6290","position":14,"is_corresponding":false},{"id":805051,"name":"Ayesha Wijesinghe","orcid":null,"position":15,"is_corresponding":false},{"id":805057,"name":"Madushika Dissanayake","orcid":null,"position":16,"is_corresponding":false},{"id":816021,"name":"Gayasha Somathilaka","orcid":null,"position":17,"is_corresponding":false},{"id":778928,"name":"Michael Harvie","orcid":null,"position":18,"is_corresponding":false},{"id":804535,"name":"Saubhagya Danasekara","orcid":"0000-0003-1776-5205","position":19,"is_corresponding":false},{"id":804533,"name":"Deshni Jayathilaka","orcid":"0000-0002-3334-2811","position":20,"is_corresponding":false},{"id":816022,"name":"Dinesh Wijayathilaka","orcid":null,"position":21,"is_corresponding":false},{"id":816023,"name":"Chinthaka Kekulandara","orcid":null,"position":22,"is_corresponding":false},{"id":555229,"name":"Lisa Schimanski","orcid":null,"position":23,"is_corresponding":false},{"id":461107,"name":"Pramila Rijal","orcid":"0000-0002-9214-9851","position":24,"is_corresponding":false},{"id":554471,"name":"Tiong Kit Tan","orcid":"0000-0001-8746-8308","position":25,"is_corresponding":false},{"id":106116,"name":"Tao Dong","orcid":"0000-0003-3545-3758","position":26,"is_corresponding":false},{"id":461108,"name":"Alain Townsend","orcid":"0000-0002-3702-0107","position":27,"is_corresponding":false},{"id":106119,"name":"Graham S. 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