COVID–19 VACCINESVIPIT INTERIM GUIDANCE 12APRIL 2021 219. See WHO statement here. The WHO has stated that a causal relationship, while plausible, has still yet to be confirmed.Clinical Presentation of VIPITPatients with VIPIT may present with cerebral sinus vein thrombosis (CSVT), or with other arterial or venous clots. Symptoms that make you suspect VIPIT include:•persistent and severe headache •focal neurological symptoms•seizures, or blurred or double vision (suggesting CSVT or arterial stroke)•shortness of breath or chest pain (suggesting pulmonary embolism or acute coronary syndrome)•abdominal pain (suggesting portal vein thrombosis) or limb swelling, redness, pallor, or coldness (suggesting deep vein thrombosis or acute limb ischemia).
VIPIT cases usually present 5 to 28 days7after vaccination, so the above symptoms occurring within this time frame should raise clinical suspicion of VIPIT.What To Do WhenAn Individual Presents with the Above Symptoms1.Ask patient about their COVID–19 vaccine history and note the date that they received the doses, if any2. Draw a complete blood count (CBC)from the patient3.If platelet count is equal or less than150 x 109/L, ANDtheir symptoms occur within 28 days after COVID–19 vaccination, such patientsare considered a suspect case of VIPIT.4. Suspect VIPIT patients need to be further evaluated for VIPIT through D–dimer and fibrinogen levels, blood films drawn to confirm thrombocytopenia,PF4 antibody assay (ELISA HIT assay),and imaging(e.g. CT or MRI) to rule out in particular CSVT.a. Cases are often characterized also with very raised D Dimerlevels(>4000 mcg/L)above the level expected for VTE and many develop low fibrinogen levels.b. Antibodies to platelet factor 4 (PF4), as detected by ELISA Heparin–Induced Thrombocytopenia (HIT) assay,have also been identified in this syndrome.5.
If such lab tests and services in #4 are not available in your clinic, you need to organize areferral to a local hospitalwith theseservices, or medically evacuateto rule out and/or treat VIPIT. A summary of these steps isfoundin Annex 1.Treatment of VIPITTreatment of suspect or confirmed VIPIT requires consultation with a specialist hematologist. However, pleasebear in mind the following principles for treating such patients:1.DO NOT giveheparin7https://b–s–h.org.uk/media/19530/guidance–version–13–on–mngmt–of–thrombosis–with–thrombocytopenia–occurring–after–c–19–vaccine_20210407.pdf
COVID–19 VACCINESVIPIT INTERIM GUIDANCE 12APRIL 2021 32.Avoidplatelettransfusions3.Consult a hematologist (in person, virtually, by phone)4.Give intravenous immunoglobulin 1 g/kg daily for 2 days for severe or life–threatening clots,if available.Further IVIG may require balancing bleeding and thrombotic ris5.Use first line anticoagulants: direct oral anti–Xa inhibitors (e.g. rivaroxaban, apixaban, edoxaban)
Until VIPIT has been ruled out, anticoagulation with heparin (both unfractionated heparin and low molecular weight heparins) should not be given. Platelet transfusionsshould not be given. Further information concerning specialized guidance on how to confirm VIPITdiagnosis and its clinical management is available at UK: Guidance Produced from the Expert Haematology Panel (EHP) focused on Covid–19 Vaccine induced Thrombosis and Thrombocytopenia (VITT)Treatment of VIPIT
With Life Threatening Blood ClotsIn patients with confirmed VIPIT and severe or life–threatening blood clots (e.g., CSVT, splanchnic vein thrombosis), it is important to administer high doseintravenous immunoglobulin (IVIG)at 1g/kg of body weight daily for two daysurgently, if available.This treatment should beguided by a consulting hematologistand can be given whilst awaiting confirmatory diagnosis.Reporting VIPITPrompt reportingof such cases amongst UN personnel is essential to learn more about this rare but serious thrombotic phenomenon.
All cases of thrombosis, thrombocytopenia occurring within 28 days of COVID–19 vaccine must be reported immediately toDHMOSH Public Health atdos–dhmosh–public–firstname.lastname@example.orgReferences•UK: GuidanceProduced from the Expert Haematology Panel (EHP) focused on Covid–19 Vaccine induced Thrombosis and Thrombocytopenia (VITT)•Ontario: Vaccine–Induced Prothrombotic Immune Thrombocytopenia (VIPIT) Following AstraZeneca COVID–19 Vaccination•Interim statement of the COVID–19 subcommittee of the WHO Global Advisory Committee on Vaccine Safety on AstraZeneca COVID–19 vaccine•https://www.ema.europa.eu/en/news/astrazenecas–covid–19–vaccine–ema–finds–possible–link–very–rare–cases–unusual–blood–clots–low–blood•NEJM: Thrombosis and Thrombocytopenia after ChAdOx1 nCoV–19 Vaccination (9 April 2021)