MMR and gelatin allergy

• Egg Allergy and MMR
  • Severe adverse reactions to MMR are very rare (1,2,3,4,5)
  • most serious adverse reactions are type 1 hypersensitivity reactions
  • reactions were originally believed to related to egg protein allergy but there is evidence that 25-33% are related to allergic reactions to gelatin hypersensitivity (2,3)
  • the safety profile of the vaccination is suggested by a study relating to proven egg allergic children who received the MMR vaccination (4):
    • 200 egg-allergic children were skin-prick tested with measles or MMR vaccine, and only 5 had positive reactions. One of these 5 developed anaphylaxis after a subsequent intradermal test. All the other 199 individuals received measles or MMR vaccine without problems
  • a further study revealed that over 400 children with documented egg allergy received the MMR vaccine first dose
    • minor reactions (not requiring treatment) occurred in four, and no major reactions occurred (5)
  • because more allergic reactions after MMR vaccination have occurred in individuals without egg hypersensitivity, other allergenic vaccine components have been sought. Previous systemic reactions to neomycin contraindicate vaccination but are extremely rare. Contact dermatitis from neomycin does not prevent immunization
  • Recent data suggest that anaphylactic reactions to MMR vaccine are not associated with hypersensitivity to egg antigens. All children with egg allergy should receive the MMR vaccination as a routine procedure in primary care (6)
    
    
• Gelatin Allergy and MMR
  • the sensitivity to development of type 1 hypersensitivity reactions to gelatin seems to higher in certain ethnic groups e.g. Japanese. Gelatin, which is prepared by the hydrolysis of collagen from various animal sources, is used as a stabilizer pharmaceutically and in foods such as yogurt, pudding, pastry, instant whipped cream, and candies. Hypersensitivity to gelatin in candy has been reported, but allergic reactions seem to be more common toward pharmaceutically used gelatin, with even fatal reactions occurring against gelatin- containing plasma substitutes
  • a separate question is how gelatin allergy has already developed in some children during the first year of life. Precooked infant foods or previous administration of gelatin-containing vaccines, such as diphtheria-tetanus-pertussis vaccine, have been postulated as sensitizing allergens (2)
    
    
• Risk of Severe Adverse Reaction on First or subsequent injection
  • in a reported series (1) 2, 990 000 doses of MMR vaccine were distributed to 1.8 million individuals. There were 73 presumed allergic reactions. There were 30 cases of urticaria and 30 cases of anaphylaxis
  • further analysis of 36 samples was undertaken including detailed which revealed that 17/36 developed the allergic reaction within 10 minutes
  • also of note is that the frequency of allergic reactions was significantly higher with the first MMR vaccine 69.4% versus 27.8% after the second vaccination (the remaining 2.8% represents missing data)
  • thus this study would suggest that the main risk of allergic reaction with MMR is with the first dose. A second dose does have a risk of allergic reaction but this is reduced in comparison to the first dose

Reference:

• Patja A et al. Allergic reactions to measles-mumps-rubella vaccination. Pediatrics 2001 Feb;107(2):E27.
• Sakaguchi M, Yoshida T, Asahi T, Aoki T, Miyatani Y, Inouye S. Development of IgE antibody to gelatin in children with systemic immediate-type reactions to vaccines. J Allergy Clin Immunol. 1997;99: 720-72194;309:223-225
• Sakaguchi M, Nakayama T, Inouye S. Food allergy to gelatin in children with systemic immediate-type reactions, including anaphylaxis, to vaccines. J Allergy Clin Immunol. 1996;98:1058-1061
• Baxter DN. Measles immunization in children with a history of egg allergy. Vaccine. 1996;14:131-134.
• Aickin R, Hill D, Kemp A. Measles immunisation in children with allergy to egg. BMJ. 1994 Jul 23;309(6949):223-5.
• The Green Book. Chapter 6 - Contraindications and special considerations (April 2019).