{"doi":"10.1093/jalm/jfad042","title":"Association between SARS-CoV-2 Symptoms, Ct Values, and Serological Response in Vaccinated and Unvaccinated Healthcare Personnel","abstract":"BACKGROUND: SARS-CoV-2 vaccines are effective at reducing symptomatic and asymptomatic COVID-19. Limited studies have compared symptoms, threshold cycle (Ct) values from reverse transcription (RT)-PCR testing, and serological testing results between previously vaccinated vs unvaccinated populations with SARS-CoV-2 infection. METHODS: Healthcare personnel (HCP) with a positive SARS-CoV-2 RT-PCR test within the previous 14 to 28 days completed surveys including questions about demographics, medical conditions, social factors, and symptoms of COVID-19. Ct values were observed, and serological testing was performed for anti-nucleocapsid (anti-N) and anti-Spike (anti-S) antibodies at enrollment and 40 to 90 days later. Serological results were compared to HCP with no known SARS-CoV-2 infection and negative anti-N testing. RESULTS: There were 104 unvaccinated/not fully vaccinated and 77 vaccinated HCP with 2 doses of an mRNA vaccine at time of infection. No differences in type or duration of symptoms were reported (P = 0.45). The median (interquartile range [IQR]) Ct was 21.4 (17.6-24.6) and 21.5 (18.1-24.6) for the unvaccinated and vaccinated HCP, respectively. Higher anti-N IgG was observed in unvaccinated HCP (5.08 S/CO, 3.08-6.92) than vaccinated (3.61 signal to cutoff ratio [S/CO], 2.16-5.05). Anti-S IgG was highest among vaccinated HCP with infection (34 285 aribitrary units [AU]/mL, 17 672-61 775), followed by vaccinated HCP with no prior infection (1452 AU/mL, 791-2943), then unvaccinated HCP with infection (829 AU/mL, 290-1555). Anti-S IgG decreased 1.56% (0.9%-1.79%) per day in unvaccinated and 0.38% (0.03%-0.94%) in vaccinated HCP. CONCLUSIONS: Vaccinated HCP infected with SARS-CoV-2 reported comparable symptoms and had similar Ct values relative to unvaccinated. However, vaccinated HCP had increased and prolonged anti-S and decreased anti-N response relative to unvaccinated.","journal":"The Journal of Applied Laboratory Medicine","year":2023,"id":384418,"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":0.9389,"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":388577,"name":"Caroline A. O’Neil","orcid":"0000-0003-2966-0750","position":1,"is_corresponding":false},{"id":1151963,"name":"Claire Dalton","orcid":null,"position":2,"is_corresponding":false},{"id":36269,"name":"David McDonald","orcid":"0000-0002-2410-9364","position":3,"is_corresponding":false},{"id":964082,"name":"Lucy Vogt","orcid":"0000-0002-8221-260X","position":4,"is_corresponding":false},{"id":698310,"name":"Karl Hock","orcid":"0000-0002-1933-6917","position":5,"is_corresponding":false},{"id":1151964,"name":"Olivia Arter","orcid":null,"position":6,"is_corresponding":false},{"id":246793,"name":"Meghan A. Wallace","orcid":"0000-0002-5518-077X","position":7,"is_corresponding":false},{"id":497194,"name":"Carol E. Muenks","orcid":"0000-0003-4294-8134","position":8,"is_corresponding":false},{"id":1151965,"name":"Mostafa Amor","orcid":null,"position":9,"is_corresponding":false},{"id":876720,"name":"Kelly Alvarado","orcid":null,"position":10,"is_corresponding":false},{"id":490498,"name":"Kate Peacock","orcid":"0000-0003-2379-0335","position":11,"is_corresponding":false},{"id":1151966,"name":"Kevin Jolani","orcid":null,"position":12,"is_corresponding":false},{"id":788160,"name":"Victoria J. Fraser","orcid":"0000-0001-6251-0733","position":13,"is_corresponding":false},{"id":246794,"name":"Carey‐Ann D. Burnham","orcid":"0000-0002-1137-840X","position":14,"is_corresponding":false},{"id":616169,"name":"Hilary M. Babcock","orcid":"0000-0001-9015-8378","position":15,"is_corresponding":false},{"id":1151967,"name":"Phillip J Budge","orcid":null,"position":16,"is_corresponding":false},{"id":255060,"name":"Jennie H. Kwon","orcid":"0000-0002-7824-6276","position":17,"is_corresponding":false},{"id":555572,"name":"Christopher W Farnsworth","orcid":"0000-0001-7169-3850","position":0,"is_corresponding":true}],"reference_count":67,"raw_metadata":null,"created_at":"2026-07-19T01:17:33.041385Z","pmid":"37478837","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":[]}