In early December, two healthcare workers experienced anaphylactic reactions to the vaccine leading to a temporary pause in using the vaccine in people with a history of severe allergies (whether to vaccines, medicines or food) and a flurry of media headlines.
On December 30, the MHRA updated its advice saying that it had found no evidence of an increased risk of anaphylaxis to the vaccine among people with serious but unrelated allergy histories. It stated that – with the exception of those who have a previous history of allergic reactions to the ingredients of the vaccine or the first dose of the vaccine itself – people with allergies such as a food allergy may receive the vaccine.
“This is welcome news for people with severe allergies, but risks to the UK rollout of Covid-19 vaccines remain because of the widespread dissemination of the allergy contraindication in the media. Front page headlines in the New York Times and on CNN and the BBC all outlined vaccine risks to people with allergies. However, MHRA’s revised guidance received little media coverage,” says an editorial penned by allergy specialists published in the BMJ today.
“The reporting of allergy as synonymous with anaphylaxis is concerning, since in the UK and US 20-40% of the population has at least one allergic disease, an umbrella term for multiple clinical syndromes (allergic rhinitis, anaphylaxis, allergic asthma, conjunctivitis, eczema and contact dermatitis, food allergy, and urticaria) caused by food, aeroallergens (including pollen), and immunologically mediated adverse effects of medicines.”
Both the UK MHRA and US FDA now simply state the vaccine should not be given to people who are known to have a severe allergic reaction (such as anaphylaxis) to any component of the vaccine.
“Importantly, history of severe allergy does not preclude vaccination unless that allergy is to the vaccine or its components," continues the BMJ editorial. "Only one of the excipients in the Pfizer-BioNTech vaccine is a known potential allergen, polyethylene glycol (PEG 2000), and this is an inactive ingredient in over 1000 medications.
“The Oxford-AstraZeneca vaccine does not contain PEG 2000 so remains an alternative for people with a history of allergy to this ingredient. However, there is some cross-reactivity between PEG and polysorbate 80, an ingredient in the Oxford-AstraZeneca vaccine, so evaluation by an allergy specialist may be advisable before vaccination in anyone with a suspected PEG allergy history.”
Communicating the updated advice about allergies is important for the wider vaccination campaign, write the authors.
"Vaccinators should be prepared to provide information, explain the difference between severe, moderate, and mild allergies, and clarify MHRA’s decision making. People’s views about covid vaccines may transfer to other vaccines— such as regular immunisation for themselves and their families—and future vaccines, so maintain open lines of communication, and if vaccination is declined, then reassure people that they can return."
Source: BMJ 2021; 372 doi: https://doi.org/10.1136/bmj.n120 (Published 18 January 2021): ‘Vaccinating against covid-19 in people who report allergies’