Allergy to COVID-19 vaccines: A current update

Area of Science:

• Immunology
• Vaccinology
• Allergology

Background:

• Adverse allergic reactions, including anaphylaxis, have been reported following COVID-19 vaccination.
• Rates of anaphylaxis are estimated at 2.5 and 11.1 per million for mRNA-1273 and BNT162b2 vaccines, respectively.
• Misdiagnosis of allergies to vaccine excipients can occur due to nomenclature issues or lack of suspicion.

Purpose of the Study:

• To review current data on anaphylactic reactions to BNT162b2, mRNA-1273, and AZD1222 vaccines.
• To identify and describe vaccine excipients potentially causing systemic allergic reactions.
• To explore the immunological mechanisms underlying these reactions.

Main Methods:

• Literature review of current data on COVID-19 vaccine anaphylaxis.
• Detailed examination of vaccine formulations, focusing on excipients.
• Analysis of potential immunological pathways involved in allergic reactions.

Main Results:

• Anaphylactic reaction rates for mRNA-1273 and BNT162b2 vaccines have been quantified.
• Key excipients implicated in allergic reactions include polyethylene glycol (PEG), polysorbates, and tromethamine.
• Potential immunological mechanisms are discussed in relation to these excipients.

Conclusions:

• Understanding specific excipients is crucial for diagnosing and managing vaccine-related allergies.
• Further research into immunological mechanisms can improve vaccine safety and administration protocols.
• Accurate labeling and heightened suspicion for excipient allergies are recommended.