Referral

COVID-19: Vaccine Allergy

Key Messages

This referral pathway is for patients with a history of allergic disease that raises concerns about receiving COVID vaccination.

All referrals will be reviewed by the allergy department and advice and guidance will be provided as soon as possible to avoid unnecessary delays in receiving vaccination.

A very small number of individuals have experienced anaphylaxis after Covid-19 vaccinations. Following close national surveillance, the MHRA is clear that most people, including those with allergic disease, can be vaccinated. Anyone with a previous history of allergy to a Covid-19 vaccine or a relevant excipient, should avoid that vaccine. However, it may be possible to use an alternative vaccine.

All recipients of the Novavax vaccine should be observed for a period of 15 mins. Recipients of the Pfizer BioNTech and Moderna mRNA COVID-19 vaccines should be similarly observed if possible. Patients should avoid driving for 15 minutes after vaccination due to a risk of fainting after vaccination. Facilities for management of anaphylaxis should be available at all vaccination sites.

Many people who had a reaction to a Covid-19 vaccine may be able to receive a subsequent dose as per the published flow chart in the Green Book Chapter 14a. Please check this before referral. Many people have tolerated subsequent doses of the same vaccine, and this is preferable as it avoids a lifelong allergy label.


    Toggle all

    Devon COVID Vaccine Allergy Referral form – please ensure the form is completed as fully as possible. Failure to do so may result in the referral being returned and a delay in patient assessment.

    All referrals without a Devon COVID Vaccine Allergy Referral form attached will be returned.

    Please note these need to be sent by the referring clinician and not directly from the patient.

    Patients that experience red flag symptoms should receive emergency management and be admitted to hospital via ambulance (even if symptoms have settled):

    Amended criteria for the diagnosis of anaphylaxis, proposed by the WAO Anaphylaxis Committee, 2019.

    Anaphylaxis is highly likely when any one of the following 2 criteria are fulfilled:

    1. Acute onset of an illness (minutes to several hours) with involvement of the skin, mucosal tissue, or both (e.g., generalized hives, pruritus or flushing, swollen lips-tongue-uvula)

    AND AT LEAST ONE OF THE FOLLOWING:

    a. Respiratory compromise (e.g., dyspnoea, wheeze-bronchospasm, stridor, reduced PEF, hypoxemia)

    b. Reduced BP or associated symptoms of end-organ dysfunction (e.g., hypotonia [collapse], syncope, incontinence)

    c. Severe gastrointestinal symptoms (e.g., severe crampy abdominal pain, repetitive vomiting), especially after exposure to non-food allergens

    2. Acute onset of hypotension* or bronchospasm or laryngeal involvementa after exposure to a known or highly probable allergenb for that patient (minutes to several hoursc), even in the absence of typical skin involvement.

    PEF, Peak expiratory flow; BP, blood pressure.

    *Hypotension defined as a decrease in systolic BP greater than 30% from that person's baseline, OR.

    i. Infants and children under 10 years: systolic BP less than (70 mmHg + [2 x age in years])

    ii. Adults: systolic BP less than 90 mmHg.

    aLaryngeal symptoms include: stridor, vocal changes, odynophagia.

    ballergen is a substance (usually a protein) capable of triggering an immune response that can result in an allergic reaction. Most allergens act through an IgE-mediated pathway, but some non-allergen triggers can act independent of IgE (for example, via direct activation of mast cells).

    cThe majority of allergic reactions occur within 1–2 hours of exposure, and usually much quicker. Reactions may be delayed for some food allergens (e.g., alpha-gal) or in the context of immunotherapy, occurring up to 10 hours after ingestion.”

    Patients with suspected anaphylaxis reactions should have:

    • Mast Cell Tryptase taken at least 24 hours after acute anaphylaxis, and also ideally during the reaction in line with RCUK and NICE anaphylaxis management guidelines (as soon as possible; and 1-2 hours but no later than 4 hours after onset of symptoms). 

    This is for information only – these samples are expected to be taken in hospital.

    The following groups of people can receive any of the available vaccines without prior allergy assessment (Green Book Chapter 14a Gov.UK). If there are patient-specific clinical concerns about following the Green Book guidance, then consider seeking A&G from the allergy clinic:

    • People with no history of allergy or anaphylaxis
    • People with a family history of allergies
    • People with a history of non-allergic reactions (e.g., vasovagal episodes, non-urticarial skin reactions, non-specific symptoms)
    • People with local skin reactions at the site of injection (these individuals can have a second dose of the same vaccine in any setting with observation for 30 minutes; the patient can consider premedicating with a non-sedating antihistamine 30 minutes prior to vaccination)
    • People with delayed-onset (over 2 hours) symptoms or urticaria or angioedema following vaccination that didn’t require medical attention (these individuals should be observed for 15 minutes and can consider premedication with a non-sedating antihistamine 30 minutes prior to vaccination)
    • People with immediate systemic symptoms WITHOUT evidence of cardiovascular or respiratory compromise, even if a single dose of adrenaline was given (these individuals can have the same vaccine in any vaccination setting with a 30-minute observation and can consider premedication with a non-sedating antihistamine 30 minutes prior to vaccination)
    • People with allergic diseases such as hayfever, eczema, or asthma
    • People with spontaneous urticaria and angioedema, without features of anaphylaxis (these individuals may wish to pre-dose with an antihistamine)
    • People with a history of allergy or anaphylaxis to foods or venom
    • People with a history of allergy or anaphylaxis to a single drug class (e.g., penicillins)
    • People with hypersensitivity to NSAIDs including aspirin (unless they meet other criteria for referral as below)
    • Mastocytosis
    • People with a history of anaphylaxis to any non-COVID vaccine (as long as they are not known to be allergic to any component (excipient) of the vaccine)

    Details of the excipients of the vaccines can be found at the following links:

    The mRNA vaccines (Pfizer and Moderna) contain PEG (Polyethylene glycol/Macrogol). This is a common excipient in medications, household products and cosmetics. Allergy to PEG is very rare and has only been implicated in a small proportion of Covid-19 vaccine allergies. PEG allergy is associated with a history of immediate, severe, systemic reactions including anaphylaxis to multiple classes of medications, where tolerance of PEG cannot be established.

    The Novavax Covid-19 vaccine does not contain PEG but do contain a related compound call Polysorbate 80. Polysorbate 80 is commonly found in medications, injections, and vaccinations. Allergy to Polysorbate 80 is extremely rare.

    To check for excipient tolerance please review the package inserts for the ingredient lists of tolerated medicines as ingredient lists can vary between manufacturers. Medicines with coatings commonly contain these excipients.

    Referral Criteria

    • Anaphylaxis following COVID vaccination
    • Anaphylaxis to a COVID vaccine excipient (e.g. PEG, polysorbate 80) (where tolerance of PEG cannot be established)
    • Anaphylaxis to multiple classes of drugs or vaccinations (where tolerance of PEG cannot be established)
    • Anaphylaxis to biologic medications (where tolerance of Polysorbate 80 cannot be established)
    • Recurrent spontaneous or unexplained anaphylaxis
    • People with delayed-onset (over 2 hours) symptoms following vaccination that did require medical attention

    Referral Instructions

    e-Referral Service Selection

    Specialty: Allergy

    Clinic Type: Allergy

    Service: Covid-19 Vaccine Allergy Service-Devon ICB-15N

    Referral Forms

    Devon COVID Vaccine Allergy Referral form

    Please ensure the form is completed as fully as possible. Failure to do so may result in the referral being returned and a delay in patient assessment.

    All referrals without a Devon COVID Vaccine Allergy Referral form attached will be returned.

    Please note these need to be sent by the referring clinician and not directly from the patient.

    GP Information:

    Green Book Chapter 14a Gov.UK

    Patient Information:

    Allergy UK - (Allergy and the coronavirus (COVID-19) Vaccine)

    • MHRA statement on the Oxford/Astra Zeneca vaccine and update on the Pfizer/BioNTech Vaccine

    Publication date: March 2021

    Updated to be in line with the Green Book.