RESUMO
Anaphylactic reactions following vaccination are rare. However, anaphylactic reactions towards the Pfizer-BioNTech Covid-19 vaccine were first reported in two patients in the UK and another 19 in the USA. Pegylation with polyethylene glycol (PEG) was thought to be the possible culprit. Pegylation is a common process in the manufacture of vaccines in order to prevent early degradation by the immune system. PEG is a polyether like e. g. Laureth-9, polidocanol, thesit and macrogol and is found in foodstuffs, cosmetics and personal care products as well as in liposomes and nanoparticles, as drug-delivery-system and as osmotic laxans for gastroscopies/coloscopies. Given the widespread use of PEG, reactions to vaccinations are rare and therefore no reason to exclude allergic patients in principle or indeed those who know the exact cause of a former anaphylaxis. In Germany, medical doctors are obliged to report any severe adverse reactions following vaccination; it is hoped that this procedure will help to resolve any remaining questions.