{"doi":"10.1093/ofid/ofad598","title":"Nasopharyngeal Viral Load Is the Major Driver of Incident Antibody Immune Response to SARS-CoV-2 Infection","abstract":"Abstract Background Virologic determinants of seroconversion to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were defined in a post hoc analysis of prospectively studied vaccine- and infection-naïve individuals at high risk for coronavirus disease 2019 (COVID-19). Methods This phase 3 COVID-19 prevention trial (NCT04452318) with casirivimab and imdevimab was conducted in July 2020–February 2021, before widespread vaccine availability. Placebo-treated participants who were uninfected (SARS-CoV-2 quantitative reverse transcription polymerase chain reaction [RT-qPCR] negative) and seronegative were assessed weekly for 28 days (efficacy assessment period [EAP]) for COVID-19 symptoms and SARS-CoV-2 infection by RT-qPCR of nasopharyngeal swab samples and for serostatus by antinucleocapsid immunoglobulin (Ig) G. Regression-based modeling, including causal mediation analysis, estimated the effects of viral load on seroconversion. Results Of 157/1069 (14.7%) uninfected and seronegative (for antispike IgG, antispike IgA, and antinucleocapsid IgG) participants who became infected during the EAP, 105 (65%) seroconverted. The mean (SD) maximum viral load of seroconverters was 7.23 (1.68) log10 copies/mL vs 4.8 (2.2) log10 copies/mL in those who remained seronegative; viral loads of ∼6.0 log10 copies/mL better predicted seroconversion. The mean of the maximum viral load was 7.11 log10 copies/mL in symptomatic participants vs 5.58 log10 copies/mL in asymptomatic participants. The mean duration of detectable viral load was longer in seroconverted vs seronegative participants: 3.24 vs 1.63 weeks. Conclusions Maximum SARS-CoV-2 viral load is a major driver of seroconversion and symptomatic COVID-19, with high viral loads (∼6.0 log10 copies/mL) better predicting seroconversion. Serology underestimates infection rates, incidence, and prevalence of SARS-CoV-2 infection.","journal":"Open Forum Infectious Diseases","year":2023,"id":381319,"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":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9472,"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":596858,"name":"Meagan P. O’Brien","orcid":null,"position":1,"is_corresponding":false},{"id":605874,"name":"Andrea T. Hooper","orcid":"0000-0003-1131-1229","position":2,"is_corresponding":false},{"id":616050,"name":"Eduardo Forleo‐Neto","orcid":"0000-0003-1959-8156","position":3,"is_corresponding":false},{"id":616051,"name":"Flonza Isa","orcid":"0000-0002-5422-8508","position":4,"is_corresponding":false},{"id":616052,"name":"Peijie Hou","orcid":"0000-0003-4899-7391","position":5,"is_corresponding":false},{"id":617303,"name":"Kuo‐Chen Chan","orcid":null,"position":6,"is_corresponding":false},{"id":249712,"name":"Myron S. Cohen","orcid":"0000-0001-5917-9664","position":7,"is_corresponding":false},{"id":593569,"name":"Mary Marovich","orcid":"0000-0002-8400-3748","position":8,"is_corresponding":false},{"id":616055,"name":"Jennifer D. Hamilton","orcid":"0000-0003-1236-5245","position":9,"is_corresponding":false},{"id":1146868,"name":"Boaz Hirshberg","orcid":"0000-0003-2829-3602","position":10,"is_corresponding":false},{"id":616057,"name":"Gary Herman","orcid":"0000-0003-4433-6529","position":11,"is_corresponding":false},{"id":225358,"name":"Bret J. Musser","orcid":"0000-0003-2949-211X","position":12,"is_corresponding":false},{"id":1067700,"name":"Meng Xu","orcid":"0000-0002-0544-3842","position":0,"is_corresponding":true}],"reference_count":40,"raw_metadata":null,"created_at":"2026-07-19T01:17:08.831117Z","pmid":"38111750","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":[]}