Potential Triggers for Thrombocytopenia and/or Hemorrhage by the BNT162b2 Vaccine, Pfizer-BioNTech

Abstract

Immune thrombocytopenia is an autoimmune disease that can cause bleeding in severe cases. Although available published data do not associate the BNT162b2 vaccine (Pfizer-BioNTech) with the risk of developing thrombocytopenia, the ChAdOx1 nCov-19 vaccine has raised concerns about its potential link with thrombosis and thrombocytopenia. We would like to clarify whether the BNT162b2 vaccine administration may interfere with pre-existing conditions and whether it may cause a risk of thrombocytopenia. Herein, we report three cases of post-vaccine thrombocytopenia among patients with rheumatoid arthritis (RA); one case in which a causal relationship cannot be ruled out with the BNT162b2 vaccine was officially announced. Furthermore, we reviewed reports of adverse events and death cases with a focus on thrombocytopenia and hemorrhages, following vaccination with BNT162b2 in Japan between February 17, 2021 and July 16, 2021, as reported by the Ministry of Health, Labour, and Welfare within the general population. The three cases in this report share the common features of old age, RA, chronic renal failure or hypertension, and pre-existing mild thrombocytopenia at baseline. A total of 746 death cases were reported during this time period, with death by bleeding accounting for 8.8% of the total deaths, of which 84.8% were cranial and statistically higher in young women than among elderly women. The risk-benefit ratio of the vaccine needs to be reconsidered based on high- and low-risk population types and ethnicity. To do so, the expansion of the pharmacovigilance system for BNT162b2 vaccination is urgently required worldwide.

Clinical and Molecular Characterization of a Rare Case of BNT162b2 mRNA COVID-19 Vaccine-Associated Myositis

“…Although BNT162b2 COVID-19 vaccination is safe and most of the adverse effects are mild [ 54 ], some moderate to serious adverse events such as anaphylaxis [ 24 , 25 , 26 , 27 ], thrombocytopenia [ 28 , 29 , 30 , 31 ], myocarditis [ 32 , 33 , 34 , 35 , 36 ], myositis [ 37 , 38 , 39 , 40 , 41 ] and rhabdomyolysis [ 42 , 43 , 44 ] were recently reported. Therefore, it is crucial to identify the factors associated with adverse effects after BNT162b2 vaccination.…”

“…Recently, several mild to moderate rare cases of anaphylaxis [ 24 , 25 , 26 , 27 ], thrombocytopenia [ 28 , 29 , 30 , 31 ], myocarditis [ 32 , 33 , 34 , 35 , 36 ], myositis [ 37 , 38 , 39 , 40 , 41 ], and rhabdomyolysis [ 42 , 43 , 44 ] associated with the BNT162b2 vaccine have been reported. Here, we report a rare case of BNT162b2 vaccine-associated myositis in which the patient was severely affected.…”

COVID-19—A Trigger Factor for Severe Immune-Mediated Thrombocytopenia in Active Rheumatoid Arthritis

“…Regarding the plateletassociated immunoglobulin G (PA-IgG), two of the three patients developed high titers of PA-IgG, being negative for ANA and anti-dsDNA antibody. Furthermore, two of the patients were hospitalized for severe bleeding complications (subarachnoid and subcortical hemorrhage) [58]. After this detailed description of the severe thrombocytopenia diagnosed in patients with RA in the first week after the first dose of mRNA vaccines, we could exclude this etiology for the severe thrombocytopenia in our case.…”

COVID-19, Vaccines, and Thrombotic Events: A Narrative Review

“…Very rare cases of thrombosis have been related to mRNA vaccines [61,113,117,[147][148][149][150][151][152][153][154][155][156][157][158][159][160]. In a study conducted at the Mayo Clinic on 68,266 subjects vaccinated with mRNA vaccines and as many controls, McMurry et al showed that the incidence of TSVC is not higher in the vaccinated [161].…”