Vaccination and allergy: EAACI position paper, practical aspects

Abstract

Immunization is highly effective in preventing infectious diseases and therefore an indispensable public health measure. Allergic patients deserve access to the same publicly recommended immunizations as non‐allergic patients unless risks associated with vaccination outweigh the gains. Whereas the number of reported possible allergic reactions to vaccines is high, confirmed vaccine‐triggered allergic reactions are rare. Anaphylaxis following vaccination is rare, affecting <1/100 000, but can occur in any patient. Some patient groups, notably those with a previous allergic reaction to a vaccine or its components, are at heightened risk of allergic reaction and require special precautions. Allergic reactions, however, may occur in patients without known risk factors and cannot be predicted by currently available tools. Unwarranted fear and uncertainty can result in incomplete vaccination coverage for children and adults with or without allergy. In addition to concerns about an allergic reaction to the vaccine itself, there is fear that routine childhood immunization may promote the development of allergic sensitization and disease. Thus, although there is no evidence that routine childhood immunization increases the risk of allergy development, such risks need to be discussed.

Allergic reactions after vaccination: translating guidelines into clinical practice

“…Several components of a vaccine may elicit hypersensitivity reactions, although with different incidence and clinical features (28,29,31). Microbial antigens: -toxoids (tetanus and diphtheria).…”

“…Recently, the discovery of traces of cow's milk in diphtheria and tetanus vaccines has suggested milk allergy involvement in the cases of anaphylaxis (see below) (48); -the mutant, non-toxic form of diphtheria toxin (CRM (197) is a component of some conjugated vaccines, and has been implicated in two cases of allergic reactions: one with prevenar-13 ® (45) and the other with haemophilus influenzae B (49); -virus-like particles of HPV could favor anaphylaxis (50), triggered by polysorbate 80 (stabilizer of quadrivalent vaccine) (51). Stabilizers: -porcine and bovine gelatin, traceable in vaccines against measles/mumps/rubella (MMR, old brands), varicella, influenza and tick borne encephalitis (28). In the past decades, MMR vaccines contained higher quantities of gelatin and episodes of anaphylaxis were much more frequent (31); -Dextran, which has been withdrawn from the market.…”

“…Adjuvants and preservatives: -thimerosal, formaldehyde, phenoxyethanol, aluminium hydroxide an aluminium phosphate are the most well known. They are usually associated to delayed cutaneous reactions (28). To date the use of thimerosal has dropped due to its mercury content (52); (40) and (41), notes from (33) to (39) are adapted from notes (28) and (31).…”

“…Latex: -from vaccine vials (e.g. HBV) or syringe plungers (28). Alpha gal: -contained in porcine gelatin or cow's milk residual, has been recently implicated in a case of anaphylaxis after zoster vaccine in a patient with known red meat allergy (58).…”

“…As for systemic reactions, it is important for health workers to be able to distinguish between panic, vasovagal and hypotonic hyporesponsive reactions and anaphylaxis (see table IV Differentiation of anaphylaxis and vasovagal reaction in EAACI position paper, (28)). Anaphylaxis is defined and diagnosed according to Sampson's criteria (figure 1) and acute management requires immediate intramuscolar epinephrine administration and AB-CDE assessment, as stated in EAACI anaphylaxis guidelines (60).…”