{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T23:56:29Z","timestamp":1790034989761,"version":"4.0.1"},"reference-count":48,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T00:00:00Z","timestamp":1701043200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000780","name":"EU Horizon 2020 research and innovation program","doi-asserted-by":"publisher","award":["101016167"],"award-info":[{"award-number":["101016167"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Regional Health Authority (Azienda Zero)","award":["101016167"],"award-info":[{"award-number":["101016167"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Introduction: The impact of long-COVID-19 syndrome is rather variable, since it is influenced by several residual confounders. This study aimed to investigate the prevalence of long COVID-19 in healthcare workers (HCWs) from four university hospitals in north-eastern Italy: Trieste, Padua, Verona, and Modena-Reggio Emilia. Methods: During the period June 2022\u2013August 2022, HCWs were surveyed for past COVID-19 infections, medical history, and any acute as well as post-COVID-19 symptoms. The prevalence of long COVID-19 was estimated at 30\u201360 days or 61+ days since first negative swab following first and second COVID-19 episode. Furthermore, the risk of long COVID-19 was investigated by multivariable logistic regression. Results were expressed as the adjusted odds ratio (aOR) with a 95% confidence interval (95%CI). Results: 5432 HCWs returned a usable questionnaire: 2401 were infected with SARS-CoV-2 at least once, 230 were infected at least twice, and 8 were infected three times. The prevalence of long COVID-19 after a primary COVID-19 infection was 24.0% at 30\u201360 days versus 16.3% at 61+ days, and 10.5% against 5.5% after the second SARS-CoV-2 event. The most frequent symptoms after a first COVID-19 event were asthenia (30.3%), followed by myalgia (13.7%), cough (12.4%), dyspnea (10.2%), concentration deficit (8.1%), headache (7.3%), and anosmia (6.5%), in decreasing order of prevalence. The risk of long COVID-19 at 30\u201360 days was significantly higher in HCWs hospitalized for COVID-19 (aOR = 3.34; 95%CI: 1.62; 6.89), those infected with SARS-CoV-2 during the early pandemic waves\u2014namely the Wuhan (aOR = 2.16; 95%CI: 1.14; 4.09) or Alpha (aOR= 2.05; 95%CI: 1.25; 3.38) transmission periods\u2014and progressively increasing with viral shedding time (VST), especially 15+ days (aOR = 3.20; 95%CI: 2.07; 4.94). Further determinants of long COVID-19 at 30\u201360 days since primary COVID-19 event were female sex (aOR = 1.91; 95%CI: 1.30; 2.80), age &gt;40 years, abnormal BMI, or administrative services (reference category). In contrast, HCWs vaccinated with two doses before their primary infection (aOR = 0.57; 95%CI: 0.34; 0.94), undergraduate students, or postgraduate medical trainees were less likely to experience long COVID-19 at 30\u201360 days. Apart from pandemic waves, the main determinants of long COVID-19 at 30\u201360 days were confirmed at 61+ days. Conclusions: The risk of long COVID-19 following primary infection increased with the severity of acute disease and VST, especially during the initial pandemic waves, when more virulent viral strains were circulating, and susceptibility to SARS-CoV-2 was higher since most HCWs had not been infected yet, COVID-19 vaccines were still not available, and\/or vaccination coverage was still building up. The risk of long COVID-19 therefore decreased inversely with humoral immunity at the individual level. Nevertheless, the prevalence of long COVID-19 was remarkably lower after SARS-CoV-2 reinfections regardless of vaccination status, suggesting that hybrid humoral immunity did not increase protection against the syndrome compared to immunity mounted by either natural infection or vaccination separately. Since the risk of long COVID-19 is currently low with Omicron and patients who developed the syndrome following SARS-CoV-2 infection in the early pandemic waves tend to return to a state of full health with time, a cost-effective approach to screen post-COVID-19 symptoms during the Omicron time could be restricted to vulnerable individuals developing severe disease and\/or with prolonged VST.<\/jats:p>","DOI":"10.3390\/vaccines11121769","type":"journal-article","created":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T11:54:48Z","timestamp":1701086088000},"page":"1769","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":45,"title":["A Multi-Center Study Investigating Long COVID-19 in Healthcare Workers from North-Eastern Italy: Prevalence, Risk Factors and the Impact of Pre-Existing Humoral Immunity\u2014ORCHESTRA Project"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6285-7355","authenticated-orcid":false,"given":"Luca","family":"Cegolon","sequence":"first","affiliation":[{"name":"Occupational Medicine Unit, Department of Medical, Surgical & Health Sciences, University of Trieste, 34129 Trieste, Italy"},{"name":"Occupational Medicine Unit, University Health Agency Giuliano-Isontina (ASUGI), 34129 Trieste, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1317-3448","authenticated-orcid":false,"given":"Marcella","family":"Mauro","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Department of Medical, Surgical & Health Sciences, University of Trieste, 34129 Trieste, Italy"},{"name":"Occupational Medicine Unit, University Health Agency Giuliano-Isontina (ASUGI), 34129 Trieste, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Donatella","family":"Sansone","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Department of Medical, Surgical & Health Sciences, University of Trieste, 34129 Trieste, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alice","family":"Tassinari","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Department of Medical, Surgical & Health Sciences, University of Trieste, 34129 Trieste, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1267-1632","authenticated-orcid":false,"given":"Fabrizio Maria","family":"Gobba","sequence":"additional","affiliation":[{"name":"Department of Biomedical, Metabolic and Neurological Sciences, University of Modena and Reggio-Emilia, 41125 Modena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0850-5615","authenticated-orcid":false,"given":"Alberto","family":"Modenese","sequence":"additional","affiliation":[{"name":"Department of Biomedical, Metabolic and Neurological Sciences, University of Modena and Reggio-Emilia, 41125 Modena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Loretta","family":"Casolari","sequence":"additional","affiliation":[{"name":"Health Surveillance Service, Modena University Hospital, 41125 Modena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4497-9287","authenticated-orcid":false,"given":"Filippo","family":"Liviero","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Padua University Hospital, 35128 Padua, Italy"},{"name":"Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, 35128 Padua, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5229-9900","authenticated-orcid":false,"given":"Sofia","family":"Pavanello","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Padua University Hospital, 35128 Padua, Italy"},{"name":"Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, 35128 Padua, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4740-4865","authenticated-orcid":false,"given":"Maria Luisa","family":"Scapellato","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Padua University Hospital, 35128 Padua, Italy"},{"name":"Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, 35128 Padua, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4728-6686","authenticated-orcid":false,"given":"Francesco","family":"Taus","sequence":"additional","affiliation":[{"name":"Department of Diagnostics and Public Health, Section of Medical Statistics, University of Verona, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3620-8765","authenticated-orcid":false,"given":"Angela","family":"Carta","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Verona University Hospital, 37134 Verona, Italy"},{"name":"Department of Diagnostics and Public Health, Section of Occupational Medicine, University of Verona, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8536-7095","authenticated-orcid":false,"given":"Gianluca","family":"Spiteri","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Verona University Hospital, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4951-2528","authenticated-orcid":false,"given":"Maria Grazia Lourdes","family":"Monaco","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Verona University Hospital, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3564-7202","authenticated-orcid":false,"given":"Stefano","family":"Porru","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Verona University Hospital, 37134 Verona, Italy"},{"name":"Department of Diagnostics and Public Health, Section of Occupational Medicine, University of Verona, 37134 Verona, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7717-0417","authenticated-orcid":false,"given":"Francesca","family":"Larese Filon","sequence":"additional","affiliation":[{"name":"Occupational Medicine Unit, Department of Medical, Surgical & Health Sciences, University of Trieste, 34129 Trieste, Italy"},{"name":"Occupational Medicine Unit, University Health Agency Giuliano-Isontina (ASUGI), 34129 Trieste, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,27]]},"reference":[{"key":"ref_1","unstructured":"Garner, P. (2022, November 05). BMJ Opinion. Paul Garner: For 7 weeks I have Been through a Roller Coaster of Ill Health, Extreme Emotions, and Utter Exhaustion. Available online: https:\/\/blogs.bmj.com\/bmj\/2020\/05\/05\/paul-garner-peoplewho-have-a-more-protracted-illness-need-help-to-understand-andcope-with-the-constantly-shifting-bizarre-symptoms\/."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"224","DOI":"10.12688\/wellcomeopenres.16307.1","article-title":"Why the patient-made term \u2018long covid\u2019 is needed","volume":"5","author":"Perego","year":"2020","journal-title":"Wellcome Open Res."},{"key":"ref_3","unstructured":"Yongu, W.T. (2022). A Critical Review of Levels of Disease Development and Prevention in Epidemiology. Int. J. Hum. Kinet. Health Educ., 6, Available online: https:\/\/journals.aphriapub.com\/index.php\/IJoHKHE\/article\/view\/1490."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"100129","DOI":"10.1016\/j.lansea.2022.100129","article-title":"An observational multi-centric COVID-19 sequelae study among health care workers","volume":"10","author":"Shukla","year":"2023","journal-title":"Lancet Reg. Health Southeast. Asia"},{"key":"ref_5","unstructured":"World Health Organization (2022, November 05). A Clinical Case Definition of Post COVID-19 Condition by a Delphi Consensus. Available online: https:\/\/www.who.int\/publications\/i\/item\/WHO-2019-nCoV-Post_COVID-19_condition-Clinical_case_definition2021.1."},{"key":"ref_6","unstructured":"National Institute for Health and Care Excellence (NICE) (2022, November 05). COVID-19 Rapid Guideline: Managing the Long-Term Effects of COVID-19. Available online: https:\/\/www.nice.org.uk\/guidance\/NG188."},{"key":"ref_7","unstructured":"Centers for Disease Control and Prevention (CDC) (2022, November 05). Post-COVID Conditions: Overview for Healthcare Providers, Available online: https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/hcp\/clinical-care\/post-covid-conditions.html#."},{"key":"ref_8","unstructured":"US Department of Health & Human Services (2023, October 23). Guidance on \u201cLong COVID\u201d as a Disability under the ADA, Section 504, and Section 1557, Available online: https:\/\/www.hhs.gov\/civil-rights\/for-providers\/civil-rights-covid19\/guidance-long-covid-disabil-dity\/index.html."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e13989","DOI":"10.1111\/eci.13989","article-title":"The definition of long COVID used in interventional studies","volume":"53","author":"Haslam","year":"2023","journal-title":"Eur. J. Clin. Investig."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"ofad233","DOI":"10.1093\/ofid\/ofad233","article-title":"Systematic Review of the Prevalence of Long COVID","volume":"10","author":"Woodrow","year":"2023","journal-title":"Open Forum Infect. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"805790","DOI":"10.3389\/fpsyg.2021.805790","article-title":"Attitudes and Perceptions of Health Protection Measures Against the Spread of COVID-19 in Italy and Poland","volume":"12","author":"Lorettu","year":"2021","journal-title":"Front. Psychol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2263","DOI":"10.1016\/S0140-6736(22)00941-2","article-title":"Risk of long COVID associated with delta versus omicron variants of SARS-CoV-2","volume":"399","author":"Antonelli","year":"2022","journal-title":"Lancet"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"101762","DOI":"10.1016\/j.eclinm.2022.101762","article-title":"The prevalence and long-term health effects of Long Covid among hospitalised and non-hospitalised populations: A systematic review and meta-analysis","volume":"55","author":"Routen","year":"2023","journal-title":"eClinicalMedicine"},{"key":"ref_14","first-page":"n1944","article-title":"Long covid-mechanisms, risk factors, and management","volume":"374","author":"Crook","year":"2021","journal-title":"BMJ"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4768","DOI":"10.7150\/ijbs.75056","article-title":"Long COVID and its Management","volume":"18","author":"Koc","year":"2022","journal-title":"Int. J. Biol. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Sansone, D., Tassinari, A., Valentinotti, R., Kontogiannis, D., Ronchese, F., Centonze, S., Maggiore, A., Cegolon, L., and Larese Filon, F. (2022). Persistence of Symptoms 15 Months since COVID-19 Diagnosis: Prevalence, Risk Factors and Residual Work Ability. Life, 13.","DOI":"10.3390\/life13010097"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Cegolon, L., Magnano, G., Negro, C., Larese Filon, F., and ORCHESTRA Working Group (2023). SARS-CoV-2 Reinfections in Health-Care Workers, 1 March 2020\u201331 January 2023. Viruses, 15.","DOI":"10.3390\/v15071551"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Cegolon, L., Ronchese, F., Ricci, F., Negro, C., and Larese-Filon, F. (2022). SARS-CoV-2 Infection in Health Care Workers of Trieste (North-Eastern Italy), 1 October 2020\u20137 February 2022: Occupational Risk and the Impact of the Omicron Variant. Viruses, 28.","DOI":"10.3390\/v14081663"},{"key":"ref_19","unstructured":"COVID-19 Excess Mortality Collaborators (2022). Estimating excess mortality due to the COVID-19 pandemic: A systematic analysis of COVID-19-related mortality, 2020\u20132021. Lancet, 399, 1513\u20131536."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2240","DOI":"10.1093\/brain\/awx153","article-title":"The fatigue conundrum","volume":"140","author":"Kuppuswamy","year":"2017","journal-title":"Brain"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"ofab440","DOI":"10.1093\/ofid\/ofab440","article-title":"Long COVID and Post-infective Fatigue Syndrome: A Review","volume":"8","author":"Sandler","year":"2021","journal-title":"Open Forum Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Borges do Nascimento, I.J., von Groote, T.C., O\u2019Mathuna, D.P., Abdulazeem, H.M., Henderson, C., Jayarajah, U., Weerasekara, I., Poklepovic Pericic, T., Klapproth, H.E., and Puljak, L. (2020). Clinical, laboratory and radiological characteristics and outcomes of novel coronavirus (SARSCoV-2) infection in humans: A systematic review and series of meta-analyses. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0239235"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1002\/acn3.51350","article-title":"Persistent neurologic symptoms and cognitive dysfunction in non-hospitalized COVID-19 \u201clong haulers\u201d","volume":"8","author":"Graham","year":"2021","journal-title":"Ann. Clin. Transl. Neurol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1007\/s00408-021-00423-z","article-title":"Post-COVID-19 Symptom Burden: What is Long-COVID and How Should We Manage It?","volume":"199","author":"Sykes","year":"2021","journal-title":"Lung"},{"key":"ref_25","first-page":"106","article-title":"The international Collaborative on Fatigue Following Infection (COFFI)","volume":"6","author":"Katz","year":"2018","journal-title":"Fatigue"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"953","DOI":"10.7326\/0003-4819-121-12-199412150-00009","article-title":"The chronic fatigue syndrome: A comprehensive approach to its definition and study","volume":"121","author":"Fukuda","year":"1994","journal-title":"Ann. Intern. Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1016\/j.bbi.2011.12.009","article-title":"Genetic associations of fatigue and other symptom domains of the acute sickness response to infection","volume":"26","author":"Piraino","year":"2012","journal-title":"Brain Behav. Immun."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.bbi.2019.07.034","article-title":"Contribution of individual psychological and psychosocial factors to symptom severity and time-to-recovery after naturally occurring acute infective illness: The Dubbo Infection Outcomes Study (DIOS)","volume":"82","author":"Cvejic","year":"2019","journal-title":"Brain Behav. Immun."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1097\/00006842-199905000-00009","article-title":"Critical life events, infections, and symptoms during the year preceding chronic fatigue syndrome (CFS): An examination of CFS patients and subjects with a nonspecific life crisis","volume":"61","author":"Theorell","year":"1999","journal-title":"Psychosom. Med."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"719","DOI":"10.5664\/jcsm.2276","article-title":"Sleep abnormalities in chronic fatigue syndrome\/myalgic encephalomyelitis: A review","volume":"8","author":"Jackson","year":"2012","journal-title":"J. Clin. Sleep. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e17600","DOI":"10.1097\/MD.0000000000017600","article-title":"Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis\/chronic fatigue syndrome: A systematic review and meta-analysis","volume":"98","author":"Nelson","year":"2019","journal-title":"Medicine"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1038\/nrendo.2011.153","article-title":"Hypothalamic-pituitary-adrenal axis dysfunction in chronic fatigue syndrome","volume":"8","author":"Papadopoulos","year":"2011","journal-title":"Nat. Rev. Endocrinol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1176\/appi.ajp.160.2.221","article-title":"Chronic fatigue syndrome: A review","volume":"160","author":"Afari","year":"2003","journal-title":"Am. J. Psychiatry"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"00056","DOI":"10.1183\/23120541.00056-2022","article-title":"Pulmonary function test and computed tomography features during follow-up after SARS, MERS and COVID-19: A systematic review and meta-analysis","volume":"8","author":"Huntley","year":"2022","journal-title":"ERJ Open Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"812","DOI":"10.1164\/rccm.202005-1583OC","article-title":"Characterization of the inflammatory response to severe COVID-19 illness","volume":"202","author":"McElvaney","year":"2020","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"E177","DOI":"10.1148\/radiol.2021203153","article-title":"Six-month follow-up chest CT findings after severe covid-19 pneumonia","volume":"299","author":"Han","year":"2021","journal-title":"Radiology"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1097\/PSY.0000000000000061","article-title":"Characterization of fatigue states in medicine and psychiatry by structured interview","volume":"76","author":"Bennett","year":"2014","journal-title":"Psychosom. Med."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"101019","DOI":"10.1016\/j.eclinm.2021.101019","article-title":"Characterizing long COVID in an international cohort: 7 months of symptoms and their impact","volume":"38","author":"Davis","year":"2021","journal-title":"eClinicalMedicine"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Cegolon, L., Pol, R., Simonetti, O., Larese Filon, F., and Luzzati, R. (2023). Molnupiravir, Nirmatrelvir\/Ritonavir, or Sotrovimab for High-Risk C OVID-19 Patients Infected by the Omicron Variant: Hospitalization, Mortality, and Time until Negative Swab Test in Real Life. Pharmaceuticals, 16.","DOI":"10.3390\/ph16050721"},{"key":"ref_40","unstructured":"UK Government (2023, October 23). NERVTAG: Update Note on B.1.1.7 Severity, 11 February 2021, Available online: https:\/\/www.gov.uk\/government\/publications\/nervtag-update-note-on-b117-severity-11-february-2021."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"e012328","DOI":"10.1136\/bmjgh-2023-012328","article-title":"Severity and Outcomes of Omicron Variant of SARS-CoV-2 Compared to Delta Variant and Severity of Omicron Sublineages: A Systematic Review and Metanalysis","volume":"8","author":"Relan","year":"2023","journal-title":"BMJ Glob. Health"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1016\/j.cell.2022.01.014","article-title":"Multiple early factors anticipate post-acute COVID-19 sequelae","volume":"185","author":"Su","year":"2022","journal-title":"Cell"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Cegolon, L., Mastrangelo, G., Emanuelli, E., Camerotto, R., Spinato, G., and Frezza, D. (2022). Early Negativization of SARS-CoV-2 Infection by Nasal Spray of Seawater plus Additives: The RENAISSANCE Open-Label Controlled Clinical Trial. Pharmaceutics, 14.","DOI":"10.3390\/pharmaceutics14112502"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Basso, P., Negro, C., Cegolon, L., and Larese Filon, F. (2022). Risk of Vaccine Breakthrough SARS-CoV-2 Infection and Associated Factors in Healthcare Workers of Trieste Teaching Hospitals (North-Eastern Italy). Viruses, 14.","DOI":"10.3390\/v14020336"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1038\/s41579-022-00846-2","article-title":"Long COVID: Major findings, mechanisms and recommendations","volume":"21","author":"Davis","year":"2023","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"611.e9","DOI":"10.1016\/j.cmi.2021.11.002","article-title":"Female gender is associated with long COVID syndrome: A prospective cohort study","volume":"28","author":"Bai","year":"2022","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_47","first-page":"247","article-title":"Post-COVID-19 syndrome among healthcare workers in Jordan","volume":"29","author":"Hyassat","year":"2023","journal-title":"EMHJ"},{"key":"ref_48","first-page":"41","article-title":"Examining Male Predominance of Severe COVID-19 Outcomes: A Systematic Review","volume":"3","author":"Twitchell","year":"2022","journal-title":"Androg. Clin. Res. Ther."}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/11\/12\/1769\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:31:52Z","timestamp":1760131912000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/11\/12\/1769"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,27]]},"references-count":48,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["vaccines11121769"],"URL":"https:\/\/doi.org\/10.3390\/vaccines11121769","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,27]]}}}