Table 1.
Characteristics of the serious complications caused by COVID-19 vaccines.
| Vaccine Complications | Most Common Vaccine Type | Incidence | Possible pathogenetic mechanisms | Clinical presentation | Special Considerations for treatment or prevention |
|---|---|---|---|---|---|
| Anaphylaxis | mRNA vaccines (BNT162b2 and mRNA-1273) | 11.1 cases per million doses | Immediate generalized IgE-mediated hypersensitivity reaction. Potential allergens: Polyethylene glycol (PEG) (mRNA vaccines) and polysorbate (vector-based vaccines) | Flashing, eruption, urticaria, angioedema, airway and/or breathing and/or cardiovascular compromise | For (confirmed) severe allergic reactions after the first vaccine dose, the Centers for Disease Control and Prevention (CDC) and the World Allergy Organization (WAO) recommend against the administration of second dose and maybe the substitution of an mRNA vaccine with a non-mRNA for the second dose |
| Vaccine-induced Thrombotic Thrombocytopenia | Αdenoviral vector-based vaccines (ChAdOx1 CoV-19 and Ad26.COV2.S) | 0.73 cases per 100,000 individuals | Activation of the platelets by the anti-PF4a antibodies, leading to arterial/venous thrombosis and platelet consumption | Arterial and/or venous thrombosis (usually cerebral and abdominal thrombosis) - Low platelet count, high d-dimers (>4 times upper limit of normal) and positive anti-PF4aantibodies | High dose IVIGa with or without corticosteroids and non-heparin anticoagulation-In refractory cases, plasma exchange and complement inhibition with eculizumab |
| Myocarditis/Pericarditis | mRNA vaccines (BNT162b2 and mRNA-1273) | 12.6 cases per million doses Highest among male adolescents and young adults |
Molecular mimicry between the viral spike protein and a cardiac protein, as well as induction of immunologic pathways and a non-specific innate inflammatory response | Retrosternal chest pain, often worsened by inspiration and relieved by leaning forward and respiratory distress -High troponin and C-reactive protein levels - ST-segment elevation in the electrocardiogram - Mildly reduced to normal left ventricular ejection fraction and global hypokinesis in transthoracic echocardiogram - Abnormal findings in cardiac MRI | Non-steroidal anti-inflammatory drugs, colchicine and steroids - In patients ≤18 years old, intravenous immunoglobulin and steroids |
| Guillain-Barré syndrome | Αdenoviral vector-based vaccines (ChAdOx1 CoV-19 and Ad26.COV2.S) |
Ad26.COV2.S: 7.8 cases per million doses ChAdOx1 CoV-19: 227 cases per 51.4 million doses Highest among males aged 50–64 years |
Acute or subacute immune-mediated neurologic disease of peripheral nerves that is usually triggered by vaccines - Molecular mimicry, anti-ganglioside antibody production and complement activation | Ascending weakness in limbs or cranial nerves, flaccid paralysis and areflexia - Distal paresthesia or quadriparesis with facial diplegia-Increased cerebrospinal fluid protein with normal numbers of cells | Steroids, IVIGa and/or plasma exchange |
| Acute Transverse Myelitis | Αdenoviral vector-based vaccines (ChAdOx1 CoV-19) | Unknown (sporadic cases) | Immune-mediated neurologic disease that is usually triggered by vaccines - Molecular mimicry and bystander immune response activation | Quadriplegia or Paraplegia -Abnormal spinal cord MRI | Steroids, IVIGa |
| Acute Disseminated Encephalomyelitis | mRNA and Αdenoviral vector-based vaccines | Unknown (sporadic cases) | Immune-mediated neurologic disease that is usually triggered by vaccines - Molecular mimicry and bystander immune response activation | Abnormal brain and spinal cord MRI - Clinical manifestations of Acute Disseminated Encephalomyelitis | Steroids, IVIGa and/or plasma exchange |
| Bell's Palsy | mRNA vaccines (BNT162b2 and mRNA-1273) | Unknown (sporadic cases) | Immune-mediated neurologic disease that is usually triggered by vaccines - Molecular mimicry and bystander activation of dormant autoreactive T-cells | Unilateral facial paresis or paralysis | Steroids |
| Rhabdomyolysis | mRNA and Adenoviral vector-based vaccines | Unknown (sporadic cases) | Exaggerated immune response to vaccine adjuvants | Myalgia, weakness and dark urine -High plasma creatine kinase levels and high urine myoglobin | Intravenous hydration -In severe disease, consider urinary alkalinization |
a
Anti-PF4: antibodies against platelet factor 4, IVIG: intravenous immunoglobulin.