Doctors from the Cleveland Clinic Foundation and the Metro Hospital in Cleveland have found that children who have milk allergies may have an allergic reaction to DTaP containing vaccinations (diphtheria, acellular pertussis and tetanus).
The vaccine is cultured on casamino acids derived from cow’s milk that could cause anaphylactic shock in children who are allergic to milk products.
The doctors reviewed case notes of children receiving vaccines at their practice between September 2007 and March 2010 and found that seven children with an average age of 11 years had reactions to the vaccines. Six of the patients had a previous history of milk allergy and five of those had had severe allergic reactions to milk in the past. Four had reactions when they were exposed to only trace amounts of milk product and one was diagnosed with milk allergy via serologic testing.
All seven children had anaphylactic shock symptoms immediately after vaccination. Five had wheezing and urticaria (raised, bumpy rash), three had sneezing, nasal congestion and angioedema (a swelling of the deeper layers of skin) and two had repetitive cough. The children were treated with anti-histamines, epinephrine, inhaled beta-antagonists or corticosteroids.
An analysis was performed on two lots of DTaP vaccines and the presence of milk protein was found in one lot (30ng/mL).
The doctors concluded that "Vaccines containing tetanus, diphtheria, and acellular pertussis derived from broths containing casamino acids may present a risk to persons with severe milk allergy."
The children in this review all had elevated specific IgE antibodies to milk proteins within two years of their reaction to vaccination. It may be that some milk allergies are triggered by vaccination. When the milk proteins are injected, the body mounts an antibody response in the same way it does to vaccine viruses so that when the child is next in contact with milk proteins, the immune system reacts. The first DTaP is given at two months of age, before the child is old enough for solid foods. This could pre-dispose him to having future dairy allergies when he is older.