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Statement of the Committee Clinical Allergology of the Austrian Society for Allergology and Immunology (ÖGAI) on anaphylactoid reactions in the context of Covid-19 mRNA vaccinations, status 23.12.2020


The approval of the first Covid-19 vaccine (Comirnaty ® ) by the EMA means that the
for the first time, a safe and effective tool to detect the Sars-CoV-2
pandemic in the longer term.


Anaphylactic reactions can occur with any vaccination, but are very rare events overall (1 incident per 1 million vaccine doses administered).


So far, 8 anaphylactoid reactions have occurred in the US and UK (out of more than 500,000 vaccine doses administered) during the past 2 weeks of Covid-19 vaccinations with Pfizer/BioNTech’s preparation.


Based on the currently available information, it is currently being discussed that lipid nanoparticles and PEG (polyethylene glycol), which are used for the “packaging” of mRNA in
used in the Pfizer/BioNTech and Moderna vaccines may play a role in the development of the above-mentioned anaphylactoid reactions. However, this hypothesis is by no means certain; other factors could also be responsible for the events.


The Committee Clinical Allergology of the ÖGAI therefore states:


1) The vaccination reactions of the mRNA preparations in the registration studies so far and
Publications are comparable to known vaccinations, mild and limited in time. 1 The most common vaccination reactions include local swelling of the vaccination site, fatigue, headache, chills and fever. From today’s perspective and data, the benefits of Covid-19 vaccination with an mRNA preparation clearly outweigh the risks.


2) Anaphylactic reactions to vaccinations are very rare events overall. Since the Pfizer/BioNTech and Moderna vaccines are based on new active principles, the occurrence of any side effects (e.g. anaphylactoid reactions, etc.) must be closely monitored. Currently, data are uncertain as to whether lipid nanoparticles and PEG are the sole trigger of these very rare intolerance reactions. 2

3) According to current recommendations of the EMA, persons suffering from allergic diseases can be vaccinated with the Covid-19 vaccine from Pfizer/BioNTech. 3 Vaccination should not be administered to individuals who have a proven allergy to components of the vaccine (e.g., PEG) and have experienced a severe allergic reaction to the first dose of vaccine. As a precautionary measure, the EMA recommends, (i) that medication for the treatment of anaphylaxis, including adrenaline, is available from the doctor, (ii) the presence on site of medical personnel experienced in the immediate treatment of a shock reaction; and (iii) a follow-up time of at least 15 minutes after administration of the vaccine is given under medical supervision.


References:
1 https://www.nejm.org/doi/full/10.1056/NEJMoa2034577
2 https://www.sciencemag.org/news/2020/12/suspicions-grow-nanoparticles-pfizer-s-covid-
19-vaccine-trigger-rare-allergic-reactions?utm_campaign=news_daily_2020-12-
21&et_rid=614241691&et_cid=3606713

3 https://www.ema.europa.eu/en/medicines/human/summaries-opinion/comirnaty