An observational study to identify the prevalence of thrombocytopenia and anti-PF4/polyanion antibodies in Norwegian health care workers after COVID-19 vaccination.

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  • Additional Information
    • Source:
      Publisher: Elsevier Country of Publication: England NLM ID: 101170508 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1538-7836 (Electronic) Linking ISSN: 15387836 NLM ISO Abbreviation: J Thromb Haemost Subsets: MEDLINE
    • Publication Information:
      Publication: 2023- : [New York] : Elsevier
      Original Publication: Oxford : Blackwell Pub.
    • Subject Terms:
      COVID-19* ; Thrombocytopenia*/chemically induced ; Thrombocytopenia*/diagnosis ; Thrombocytopenia*/epidemiology; COVID-19 Vaccines ; ChAdOx1 nCoV-19 ; Europe ; Health Personnel ; Heparin ; Humans ; Norway/epidemiology ; Platelet Factor 4 ; Polyelectrolytes ; Prevalence ; SARS-CoV-2 ; Vaccination
    • Abstract:
      Background: The COVID-19 vaccine from AstraZeneca (AZD1222) is one of several vaccines introduced to provide immunity against SARS-CoV-2. Recently, more than 50 cases have been reported presenting a combination of thrombosis, thrombocytopenia, and remarkably high levels of anti-platelet factor 4 (PF4)/polyanion antibodies post-AZD1222 vaccination. Now linked to the vaccine, the condition is referred to as vaccine-induced immune thrombotic thrombocytopenia. The European Medicines Agency still recommends vaccination with AZD1222, but several European countries have temporally paused and/or restricted its use because of the perceived risk of this severe side effect. Because there is no description of PF4/polyanion antibody testing in the clinical trials, knowledge about the prevalence of such antibodies in a vaccinated cohort is needed.
      Objectives: To investigate prevalence of thrombocytopenia and anti-PF4/polyanion antibodies in a population recently vaccinated with AZD1222.
      Patients/methods: Four hundred and ninety-two health care workers recently vaccinated with the first dose of AZD1222 were recruited from two hospitals in Norway. Study individuals were screened for thrombocytopenia and the presence of anti-PF4/polyanion antibodies with a PF4/PVS immunoassay. Side effects after vaccination were registered.
      Results: The majority of study participants had normal platelet counts and negative immunoassay. Anti-PF4/polyanion antibodies without platelet activating properties were only detected in six individuals (optical density ≥0.4, range 0.58-1.16), all with normal platelet counts. No subjects had severe thrombocytopenia.
      Conclusions: We found low prevalence of both thrombocytopenia and antibodies to PF4/polyanion-complexes among Norwegian health care workers after vaccination with AZD1222.
      (© 2021 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)
    • References:
      Lancet. 2021 Jan 9;397(10269):99-111. (PMID: 33306989)
      Lancet. 2020 Aug 15;396(10249):467-478. (PMID: 32702298)
      N Engl J Med. 2001 Apr 26;344(17):1286-92. (PMID: 11320387)
      N Engl J Med. 2021 Jun 10;384(23):2202-2211. (PMID: 33861525)
      J Thromb Haemost. 2017 Nov;15(11):2099-2114. (PMID: 28846826)
      Lancet. 2021 Dec 19;396(10267):1979-1993. (PMID: 33220855)
      N Engl J Med. 2021 Jun 3;384(22):2092-2101. (PMID: 33835769)
      N Engl J Med. 2021 Jun 3;384(22):2124-2130. (PMID: 33835768)
      Am J Clin Pathol. 2010 Nov;134(5):774-80. (PMID: 20959660)
      Platelets. 2013;24(6):441-7. (PMID: 22994796)
      Lancet. 2021 Mar 6;397(10277):881-891. (PMID: 33617777)
    • Grant Information:
      2020/1100 Helse Nord RHF
    • Contributed Indexing:
      Keywords: COVID-19 vaccines; COVID-19 vaccines/adverse effects; drug related side effects and adverse reactions; platelet factor 4; thrombocytopenia
    • Accession Number:
      0 (COVID-19 Vaccines)
      0 (Polyelectrolytes)
      0 (polyanions)
      37270-94-3 (Platelet Factor 4)
      9005-49-6 (Heparin)
      B5S3K2V0G8 (ChAdOx1 nCoV-19)
    • Publication Date:
      Date Created: 20210428 Date Completed: 20210630 Latest Revision: 20230829
    • Publication Date:
      20231215
    • Accession Number:
      PMC8237070
    • Accession Number:
      10.1111/jth.15352
    • Accession Number:
      33909350