{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T12:27:42Z","timestamp":1789043262157,"version":"build-2803163510"},"reference-count":29,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,2,18]],"date-time":"2025-02-18T00:00:00Z","timestamp":1739836800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: Splenectomized\/asplenic individuals are at a heightened risk for severe infections due to compromised immune function. However, the impact of splenectomy\/asplenia on COVID-19 outcomes remains underexplored. This study aims to systematically review and meta-analyze the association between splenectomy\/asplenia and severe COVID-19 outcomes. Methods: Following the PRISMA guidelines, databases including Scopus, MEDLINE\/PubMed, and Web of Knowledge were searched for relevant articles published between January 2020 and June 2024. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for severe COVID-19 outcomes, with a random-effects model being used to account for heterogeneity. Out of 749 identified studies, 4 met the inclusion criteria. Results: The meta-analysis revealed a significant association between splenectomy\/asplenia and overall severe COVID-19 outcomes (OR = 1.92; 95% CI = 1.06\u20133.47). Specifically, splenectomy\/asplenia was significantly associated with increased COVID-19-related hospitalization (OR = 2.06; 95% CI = 1.21\u20133.49), while the association with COVID-19-related death was not statistically significant (OR = 1.52; 95% CI = 0.78\u20132.99). COVID-19 vaccination is strongly recommended for these patients. Conclusions: Splenectomy\/asplenia significantly increases the risk of severe COVID-19 outcomes, particularly hospitalization. The findings underscore the need for vigilant clinical management and targeted interventions for this vulnerable population. Further research is warranted to fully understand the risks and to develop effective guidelines for the protection of splenectomized individuals against COVID-19.<\/jats:p>","DOI":"10.3390\/vaccines13020203","type":"journal-article","created":{"date-parts":[[2025,2,18]],"date-time":"2025-02-18T09:45:23Z","timestamp":1739871923000},"page":"203","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Assessing the Vulnerability of Splenectomized Patients to Severe COVID-19 Outcomes: A Systematic Review and Meta-Analysis"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9659-0193","authenticated-orcid":false,"given":"Francesco Paolo","family":"Bianchi","sequence":"first","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7041-7851","authenticated-orcid":false,"given":"Massimo","family":"Giotta","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8068-6246","authenticated-orcid":false,"given":"Andrea","family":"Martinelli","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Grazia","family":"Giurgola","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giulia","family":"Del Matto","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elita","family":"Mastrovito","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Tina","family":"Fedele","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giuseppe","family":"Manca","sequence":"additional","affiliation":[{"name":"Surgery Department, Local Health Authority of Brindisi, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Salvatore","family":"Minniti","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Local Health Authority of Brindisi, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maurizio","family":"De Nuccio","sequence":"additional","affiliation":[{"name":"General Management, Local Health Authority of Brindisi, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincenzo","family":"Gigantelli","sequence":"additional","affiliation":[{"name":"Health Management, Local Health Authority of Brindisi, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4194-0210","authenticated-orcid":false,"given":"Silvio","family":"Tafuri","sequence":"additional","affiliation":[{"name":"Department of Interdisciplinary Medicine, University of Bari, 70121 Bari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefano","family":"Termite","sequence":"additional","affiliation":[{"name":"Health Prevention Department, Local Health Authority of Brindisi, Via Napoli 8, 72100 Brindisi, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,18]]},"reference":[{"key":"ref_1","unstructured":"CDC (2024, June 18). People with Certain Medical Conditions, Available online: https:\/\/www.cdc.gov\/covid\/risk-factors\/index.html#:~:text=Like%20adults%2C%20children%20and%20teens,very%20sick%20from%20COVID%2D19."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.1016\/j.ijsu.2014.11.005","article-title":"Overwhelming post splenectomy infection syndrome\u2014Review study","volume":"12","author":"Sinwar","year":"2014","journal-title":"Int. J. Surg."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1080\/14760584.2021.1886085","article-title":"Immunization coverage among asplenic patients and strategies to increase vaccination compliance: A systematic review and meta-analysis","volume":"20","author":"Bianchi","year":"2021","journal-title":"Expert. Rev. Vaccines"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1017\/S0950268816002405","article-title":"Overwhelming post-splenectomy sepsis in patients with asplenia and hyposplenia: A retrospective cohort study","volume":"145","author":"Chong","year":"2017","journal-title":"Epidemiol. Infect."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4579","DOI":"10.1016\/j.vaccine.2023.06.034","article-title":"Adherence to vaccination guidelines of patients with complete splenectomy in Norway, 2008\u20132020","volume":"41","author":"Orangzeb","year":"2023","journal-title":"Vaccine"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1080\/21645515.2017.1264797","article-title":"Recommended vaccinations for asplenic and hyposplenic adult patients","volume":"13","author":"Bonanni","year":"2017","journal-title":"Hum. Vaccines Immunother."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e17698","DOI":"10.1097\/MD.0000000000017698","article-title":"The immunity features and defects against primary cytomegalovirus infection post-splenectomy indicate an immunocompromised status: A PRISMA-compliant meta-analysis","volume":"98","author":"Liatsos","year":"2019","journal-title":"Medicine"},{"key":"ref_8","unstructured":"CDC (2024, June 17). Underlying Medical Conditions Associated with Higher Risk for Severe COVID-19: Information for Healthcare Professionals, Available online: https:\/\/archive.cdc.gov\/www_cdc_gov\/coronavirus\/2019-ncov\/hcp\/clinical-care\/underlyingconditions.html."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1023","DOI":"10.1111\/bjh.18767","article-title":"COVID-19 and splenectomy: Education matters","volume":"201","author":"Crickx","year":"2023","journal-title":"Br. J. Haematol."},{"key":"ref_10","unstructured":"CDC (2024, June 11). Asplenia and Adult Vaccination. Available online: https:\/\/www.immunize.org\/catg.d\/p4047.pdf."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1038\/s41572-022-00399-x","article-title":"Asplenia and spleen hypofunction","volume":"8","author":"Lenti","year":"2022","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1080\/14760584.2022.2035222","article-title":"COVID-19 vaccine effectiveness among immunocompromised populations: A targeted literature review of real-world studies","volume":"21","author":"Lin","year":"2022","journal-title":"Expert. Rev. Vaccines"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"See, K.C. (2022). Vaccination for the Prevention of Infection among Immunocompromised Patients: A Concise Review of Recent Systematic Reviews. Vaccines, 10.","DOI":"10.3390\/vaccines10050800"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Lupo-Stanghellini, M.T., Di Cosimo, S., Costantini, M., Monti, S., Mantegazza, R., Mantovani, A., Salvarani, C., Zinzani, P.L., Inglese, M., and Ciceri, F. (2022). mRNA-COVID19 Vaccination Can Be Considered Safe and Tolerable for Frail Patients. Front. Oncol., 12.","DOI":"10.3389\/fonc.2022.855723"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"n71","DOI":"10.1136\/bmj.n71","article-title":"The PRISMA 2020 statement: An updated guideline for reporting systematic reviews","volume":"372","author":"Page","year":"2021","journal-title":"BMJ"},{"key":"ref_16","unstructured":"Wells, G.A., Shea, B., O\u2019Connell, D., Peterson, J., Welch, V., Losos, M., and Tugwell, P. (2014). The Newcastle-Ottawa Scale (NOS) for Assessing the Quality of Nonrandomised Studies in Meta-Analyses, Ottawa Health Research Institute."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1186\/s13643-021-01824-0","article-title":"Using median survival in meta-analysis of experimental time-to-event data","volume":"10","author":"Hirst","year":"2021","journal-title":"Syst. Rev."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1072","DOI":"10.1111\/bjh.18731","article-title":"Burden of COVID-19 disease and vaccine coverages in Apulian splenectomized patients: A retrospective observational study","volume":"201","author":"Bianchi","year":"2023","journal-title":"Br. J. Haematol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"894","DOI":"10.1002\/hon.3203","article-title":"The course of patients with hairy cell leukemia during the omicron surge of the COVID-19 pandemic","volume":"41","author":"Tadmor","year":"2023","journal-title":"Hematol. Oncol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"678","DOI":"10.1080\/23744235.2021.1921257","article-title":"Splenectomy and risk of COVID-19 infection, hospitalisation, and death","volume":"53","author":"Bojesen","year":"2021","journal-title":"Infect. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"430","DOI":"10.1038\/s41586-020-2521-4","article-title":"Factors associated with COVID-19-related death using OpenSAFELY","volume":"584","author":"Williamson","year":"2020","journal-title":"Nature"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"E53","DOI":"10.5888\/pcd19.210228","article-title":"COVID-19 Severity and Mortality Among Chronic Liver Disease Patients: A Systematic Review and Meta-Analysis","volume":"19","author":"Nagarajan","year":"2022","journal-title":"Prev. Chronic Dis."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Reyes, F.M., Hache-Marliere, M., Karamanis, D., Berto, C.G., Estrada, R., Langston, M., Ntaios, G., Gulani, P., Shah, C.D., and Palaiodimos, L. (2021). Assessment of the Association of COPD and Asthma with In-Hospital Mortality in Patients with COVID-19. A Systematic Review, Meta-Analysis, and Meta-Regression Analysis. J. Clin. Med., 10.","DOI":"10.3390\/jcm10102087"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1623","DOI":"10.1007\/s11255-020-02740-3","article-title":"Mortality in chronic kidney disease patients with COVID-19: A systematic review and meta-analysis","volume":"53","author":"Cai","year":"2021","journal-title":"Int. Urol. Nephrol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"101644","DOI":"10.1016\/j.cpcardiol.2023.101644","article-title":"Mortality and Complications of COVID-19 Among Adult Congenital Heart Disease Patients: A Retrospective Cohort Study Using the National Inpatient Sample Database","volume":"48","author":"Raj","year":"2023","journal-title":"Curr. Probl. Cardiol."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Ng, S.M., Pan, J., Mouyis, K., Kondapally Seshasai, S.R., Kapil, V., Rice, K.M., and Gupta, A.K. (2022). Quantifying the Excess Risk of Adverse COVID-19 Outcomes in Unvaccinated Individuals With Diabetes Mellitus, Hypertension, Ischaemic Heart Disease or Myocardial Injury: A Meta-Analysis. Front. Cardiovasc. Med., 9.","DOI":"10.3389\/fcvm.2022.871151"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Lenti, M.V., Aronico, N., Pellegrino, I., Boveri, E., Giuffrida, P., Borrelli de Andreis, F., Morbini, P., Vanelli, L., Pasini, A., and Ubezio, C. (2020). Depletion of circulating IgM memory B cells predicts unfavourable outcome in COVID-19. Sci. Rep., 10.","DOI":"10.1038\/s41598-020-77945-8"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"350","DOI":"10.7326\/M20-2566","article-title":"Pulmonary Arterial Thrombosis in COVID-19 With Fatal Outcome: Results From a Prospective, Single-Center, Clinicopathologic Case Series","volume":"173","author":"Lax","year":"2020","journal-title":"Ann. Intern. Med."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.clinimag.2021.04.035","article-title":"Does COVID-19 cause an increase in spleen dimensions? Possible effects of immune activation, hematopoietic suppression and microthrombosis","volume":"79","author":"Tahtabasi","year":"2021","journal-title":"Clin. Imaging"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/13\/2\/203\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:37:06Z","timestamp":1760027826000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/13\/2\/203"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,18]]},"references-count":29,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,2]]}},"alternative-id":["vaccines13020203"],"URL":"https:\/\/doi.org\/10.3390\/vaccines13020203","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,2,18]]}}}