In the 2012 update to the Adverse Reactions to Vaccines Practice Parameters, the contents of MMRV vaccine (ProQuad) do not list "chick embryos fibroblasts" like the MMR vaccine contents do. The Prescribing Info Sheet for ProQuad from Merck states that the measles and mumps viruses are grown in chick embryo cell cultures. Is the egg content known for MMRV? ...or is it presumed to be the same for that reported for MMR and therefore can be safely administered to egg allergic patients? Thanks.


Thank you for your inquiry.

I am referring your inquiry to Dr. James Li, who, as you know, is one of the coauthors of the Vaccine Parameters. When I hear from Dr. Li, I will forward his response to you.

Thank you again for your inquiry.

Phil Lieberman, M.D.

We received a response from Dr. James Li. Thank you again for your inquiry and we hope this response is helpful to you.

Phil Lieberman, M.D.

Response from Dr. James Li:

The measles, mumps, rubella and varicella vaccine live (MMRV, Proquad-Merck) is made up of a combination of measles, mumps, rubella and varicella vaccine components. Thus, the MMRV vaccine is essentially the MMR vaccine combined with a varicella vaccine. The measles and mumps vaccine components are propagated in chick embryo cell culture. Thus, there are trace amounts of egg protein in MMR and MMRV vaccines. The rubella and varicella vaccine components are not propagated in chick embryo cells.

The package insert of the MMR II (Merck 2009) reads in part: "Live measles vaccine and live mumps vaccine are produced in chick embryo cells culture. Persons with a history of anaphylactic, anaphylactoid or other immediate reactions (e.g., hives, swelling of the mouth and throat, difficulty breathing, hypotension, or shock) subsequent to egg ingestion may be at an enhanced risk of immediate-type hypersensitivity reactions after receiving vaccines containing traces of chick embryo antigen. The potential risk to benefit ratio should be carefully evaluated before considering vaccination in such cases. Such individuals may be vaccinated with extreme caution, having adequate treatment on hand should a reaction occur. However, the AAP has stated, 'Most children with a history of anaphylactic reactions to eggs have no untoward reactions to measles or MMR vaccine. Persons are not at increased risk if they have egg allergies that are not anaphylactic, and they should be vaccinated in the usual manner. In addition, skin testing of egg-allergic children with vaccine has not been predictive of which children will have an immediate hypersensitivity reaction. Persons with allergies to chickens or chicken feathers are not at increased risk of reaction to the vaccine.'"

The package insert of the MMRV is similar. The package inserts of the MMR and MMRV do not state egg protein levels. Previous research showed that the ovalbumin content of MMR was only 37 picograms (Fasano MB et al J Pediatrics 120:878-81, 1992).

In summary, the MMRV vaccine contains only trace amounts of egg protein, and can be administered in a similar fashion as the MMR vaccine.

James Li

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