Acute extensive pulmonary embolism after mRNA SARS-CoV-2 immunization

Area of Science:

• Immunology
• Cardiology
• Pharmacovigilance

Background:

• COVID-19 vaccines are crucial for disease control, with generally mild side effects.
• Severe adverse events, including thromboembolism, are rare but monitored post-authorization.
• Viral vector vaccines have been more frequently associated with thromboembolic events.

Observation:

• A 26-year-old female without prior risk factors developed extensive pulmonary embolism post-Pfizer-BNT162b2 mRNA vaccination.
• The patient required hospitalization, enoxaparin, and Altaplase thrombolytic therapy for treatment.
• Thrombophilia screening at six months was negative.

Findings:

• Successful treatment with anticoagulation (Apixaban) and thrombolysis led to patient recovery.
• The case demonstrates a rare instance of severe thromboembolism linked to an mRNA COVID-19 vaccine.
• Absence of pre-existing risk factors underscores the need for vigilance.

Implications:

• Highlights the importance of pharmacovigilance for detecting uncommon vaccine side effects.
• Underscores the necessity for prompt clinical recognition and management of post-vaccination thromboembolism.
• Suggests that even mRNA vaccines, while generally safe, can rarely be associated with severe adverse events.