{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,20]],"date-time":"2026-05-20T17:50:58Z","timestamp":1779299458716,"version":"3.51.4"},"reference-count":34,"publisher":"Public Library of Science (PLoS)","issue":"2","license":[{"start":{"date-parts":[[2023,2,24]],"date-time":"2023-02-24T00:00:00Z","timestamp":1677196800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Safe vaccination is essential for mitigation of the COVID-19 pandemic. Two adenoviral vector vaccines, ChAdOx1 nCov-19 (AstraZeneca) and Ad26.COV2.S (Johnson&amp;Johnson\/Janssen) have shown to be effective and they are distributed globally, but reports on serious cerebral venous sinus thrombosis (CVST) associated with thrombocytopenia, have emerged. Our objective was to evaluate the background incidence of CVST with thrombocytopenia and to compare it to incidences following COVID-19 vaccines. We conducted a register-based nation-wide cohort study in Finland, including all 5.5 million individuals alive in Finland, 1 Jan 2020. COVID-19 vaccinations registered in the National Vaccination Register served as the exposure. We detected CVST admissions or hospital visits recorded in the hospital discharge register from Jan 1, 2020 through April 2, 2021. We confirmed the diagnosis of CVST and thrombocytopenia (platelet count &lt;150,000 per cubic millimeter) using radiology reports and laboratory data. By Poisson regression, we compared the baseline incidences to the risks within four weeks after COVID-19 vaccinations. Out of the 167 CVST episodes identified in the registers, 117 were confirmed as CVST, 18 of which coincided with thrombocytopenia (baseline incidence 0.18 per 28 days per million persons). We found 2 episodes of CVST with thrombocytopenia within 28 days of the first ChAdOx1 nCov-19 vaccination (among 200,397 vaccinated, aged 16 or above). No cases were found following the first mRNA vaccine dose among 782,604 vaccinated. The background incidence of CVST combined with thrombocytopenia was minuscule compared to the incidence during the weeks following the ChAdOx1 nCov-19 vaccination. Accurate estimation of the baseline incidence is essential in the critical appraisal of the benefit-risk of any vaccination program.<\/jats:p>","DOI":"10.1371\/journal.pone.0282226","type":"journal-article","created":{"date-parts":[[2023,2,24]],"date-time":"2023-02-24T18:39:58Z","timestamp":1677263998000},"page":"e0282226","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":6,"title":["Incidence of sinus thrombosis with thrombocytopenia\u2014A nation-wide register study"],"prefix":"10.1371","volume":"18","author":[{"given":"Petteri","family":"Hovi","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arto A.","family":"Palmu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tuomo A.","family":"Nieminen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Miia","family":"Artama","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jukka","family":"Jokinen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Esa","family":"Ruokokoski","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Riitta","family":"Lassila","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hanna","family":"Nohynek","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Terhi","family":"Kilpi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2023,2,24]]},"reference":[{"key":"pone.0282226.ref001","unstructured":"WHO. 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Updated Brighton Collaboration Case Definition for Thrombosis with Thrombocytopenia Syndrome (TTS) [Internet]. 2021 Nov [cited 2021 Dec 21]. https:\/\/brightoncollaboration.us\/thrombosis-with-thrombocytopenia-syndrome-interim-case-definition\/"},{"key":"pone.0282226.ref008","doi-asserted-by":"crossref","unstructured":"Palaiodimou LMD, Stefanou MIMD, Katsanos AHMD, Aguiar de Sousa DMD, Coutinho JMMD, Lagiou PMD, et al. Cerebral venous sinus thrombosis and thrombotic events after vector-based COVID-19 vaccines: A systematic review and meta-analysis. Neurology. 2021 Forthcoming.","DOI":"10.1212\/WNL.0000000000012896"},{"key":"pone.0282226.ref009","unstructured":"EMA. European Medicines Agency. COVID-19 Vaccine AstraZeneca: benefits still outweigh the risks despite possible link to rare blood clots with low blood platelets. Mar 18 [Internet]. 2021 [cited 2021 Jul 7]. https:\/\/www.ema.europa.eu\/en\/news\/covid-19-vaccine-astrazeneca-benefits-still-outweigh-risks-despite-possible-link-rare-blood-clots"},{"issue":"11","key":"pone.0282226.ref010","doi-asserted-by":"crossref","first-page":"2099","DOI":"10.1111\/jth.13813","article-title":"Autoimmune heparin-induced thrombocytopenia","volume":"15","author":"A Greinacher","year":"2017","journal-title":"J Thromb Haemost"},{"key":"pone.0282226.ref011","unstructured":"Report on suspected cases of side effects and vaccination complications after vaccination to protect against COVID-19 (reporting period December 27 to May 31, 2021) [Internet]. Paul-Erlich-Insitut; 2021 Jun. https:\/\/www.pei.de\/SharedDocs\/Downloads\/DE\/newsroom\/dossiers\/sicherheitsberichte\/sicherheitsbericht-27-12-bis-31-05-21.html"},{"key":"pone.0282226.ref012","article-title":"Frequency of Thrombocytopenia and Platelet Factor 4\/Heparin Antibodies in Patients With Cerebral Venous Sinus Thrombosis Prior to the COVID-19 Pandemic","author":"M S\u00e1nchez van Kammen","year":"2021","journal-title":"JAMA"},{"key":"pone.0282226.ref013","unstructured":"THL. Finnish Institute for Health and Welfare. Register description, Care Register for Health Care [Internet]. 2021 [cited 2021 Dec 31]. https:\/\/thl.fi\/en\/web\/thlfi-en\/statistics-and-data\/data-and-services\/register-descriptions\/care-register-for-health-care"},{"key":"pone.0282226.ref014","unstructured":"Kanta. Kanta. Patient Data Repository [Internet]. [cited 2021 Dec 19]. https:\/\/www.kanta.fi\/en\/professionals\/patient-data-repository"},{"key":"pone.0282226.ref015","unstructured":"THL. Finnish National Infectious Diseases Register [Internet]. 2021 [cited 2021 Dec 19]. https:\/\/thl.fi\/en\/web\/infectious-diseases-and-vaccinations\/surveillance-and-registers\/finnish-national-infectious-diseases-register"},{"key":"pone.0282226.ref016","unstructured":"THL. Situation update on coronavirus [Internet]. 2021 [cited 2021 Dec 19]. https:\/\/thl.fi\/en\/web\/infectious-diseases-and-vaccinations\/what-s-new\/coronavirus-covid-19-latest-updates\/situation-update-on-coronavirus"},{"issue":"17","key":"pone.0282226.ref017","first-page":"30520","article-title":"Establishing and maintaining the National Vaccination Register in Finland","volume":"22","author":"U Baum","year":"2017","journal-title":"Euro Surveill Bull Eur Sur Mal Transm Eur Commun Dis Bull"},{"key":"pone.0282226.ref018","unstructured":"KELA. Reimbursements for medical expenses, KELA [Internet]. [cited 2021 Dec 21]. https:\/\/www.kela.fi\/web\/en\/medical-expenses"},{"key":"pone.0282226.ref019","unstructured":"Prescription Centre [Internet]. 2021 [cited 2021 Dec 21]. https:\/\/www.kanta.fi\/en\/web\/guest\/prescriptions"},{"key":"pone.0282226.ref020","first-page":"2021","article-title":"Predictors of hospitalisation and death due to SARS-CoV-2 infection in Finland: a population-based register study with implications to vaccinations","author":"H Salo","year":"2021","journal-title":"medRxiv"},{"key":"pone.0282226.ref021","unstructured":"Finlex. 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Burn","year":"2021","journal-title":"medRxiv"},{"key":"pone.0282226.ref025","doi-asserted-by":"crossref","first-page":"n1931","DOI":"10.1136\/bmj.n1931","article-title":"Risk of thrombocytopenia and thromboembolism after covid-19 vaccination and SARS-CoV-2 positive testing: self-controlled case series study","volume":"374","author":"J Hippisley-Cox","year":"2021","journal-title":"BMJ"},{"issue":"12","key":"pone.0282226.ref026","doi-asserted-by":"crossref","first-page":"3375","DOI":"10.1161\/STROKEAHA.112.671453","article-title":"The incidence of cerebral venous thrombosis: a cross-sectional study","volume":"43","author":"JM Coutinho","year":"2012","journal-title":"Stroke"},{"issue":"9","key":"pone.0282226.ref027","doi-asserted-by":"crossref","first-page":"2180","DOI":"10.1161\/STROKEAHA.116.013617","article-title":"Cerebral Venous Sinus Thrombosis Incidence Is Higher Than Previously Thought: A Retrospective Population-Based Study","volume":"47","author":"S 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