Kids May React to Milk Proteins in DPT Shot
Primary source: Journal of Allergy and Clinical Immunology
Kattan J, et al “Allergic reactions to diphtheria, tetanus, and acellular pertussis vaccines among children with milk allergy” J Allergy Clin Immunol2011; Abstract AB238.Additional source: Journal of Allergy and Clinical Immunology
Paschall V, et al “Do egg-specific IgE levels predict reactions to seasonal influenza or H1N1 vaccination?” J Allergy Clin Immunol 2011; Abstract AB182.
SAN FRANCISCO — Some children highly allergic to milk products should be watched with caution when receiving the diphtheria, pertussis, and tetanus (DPT) vaccine because trace milk proteins in the vaccine could trigger reactions, researchers suggested.
“We identified seven patients who reported convincing allergic reactions to tetanus vaccines,” reported Scott Sicherer, MD, professor of pediatrics at the Mt. Sinai School of Medicine in New York City, during his poster presentation at the annual meeting of the American Academy of Allergy, Asthma & Immunology here.
“We observed several children with severe milk allergy to have reacted to the common childhood vaccine called the DPT or tetanus booster,” Sicherer explained in an email to MedPage Today in response to questions. “We believe that the vaccine may have very trace milk protein in some lots.”
The protein was identified as casamino acids derived from cow’s milk, contained in medium used to process the vaccines.
The findings came from a chart review of patients seen at Mt. Sinai who had reported allergic reactions after receiving the vaccine (primary or booster doses) from September 2007 to March 2010.
The patients in question, five boys and two girls, had a median age of 11.
“These cases were an observation in a relatively short period of two and one-half years where we encountered seven children with milk allergy having a severe anaphylactic reaction to the injection of the DPT shot,” said co-author Hugh Sampson, MD, director of the Jaffe Food Allergy Institute at Mt. Sinai.
“These were all children who had high levels of immunoglobulin antibody to milk protein,” Sampson remarked at a press briefing. “In two of the cases we were able to find that even though the children were from different areas they received the same lot of vaccine.”
“We then used a very sensitive immunoassay to look for the presence of milk protein in vials of Adacel which was the DPT that they received. Of the two vials we looked at, one of them clearly had milk protein in it,” he added.
“We are looking at more lots to get an idea whether this is an uncommon phenomenon or not,” Sampson said. “We were struck by the fact that just in our practice we had seven patients with milk allergy who had these severe reactions and we believe it is due to contamination of milk protein in this vaccine.”
“This is very preliminary,” Sicherer commented, “but if I had an extremely milk allergic subject I would take caution.”
Sicherer suggested that more studies are needed to understand the problems raised by the observations.
The doctors noted that six of the patients had prior allergic reactions to cow’s milk. Of those seven reactions, Sicherer and colleagues classified five as severe reactions.
In the study, the researchers reported that after receiving the vaccine, the children exhibited the following symptoms:
Five of the children were treated with antihistamines and three were treated with epinephrine.
Three of the seven children were also administered inhaled beta-agonists and two were given corticosteroids, either as monotherapy or in combinations, the researchers reported.
“We have also looked at vaccines, and food allergy reactions are very rare,” Roxana Siles, MD, a fellow in allergy and immunology at the Cleveland Clinic Foundation, told MedPage Today. “In our experience, these kids do just fine.”
Siles and colleagues conducted a retrospective chart review of 62 children (49 boys and 13 girls) around 4 years old with confirmed egg allergy, who had received seasonal influenza and/or H1N1 vaccination at the Cleveland Clinic’s tertiary care center during 2009-2010.
Both H1N1 influenza and seasonal influenza vaccinations are created using eggs.
Of the 131 injections given to the children, there was only one small local reaction.
Twenty of the children who had been previously diagnosed with egg allergies underwent skin testing prior to inoculation; seven had positive skin tests.
Three of the children were given split doses of the vaccine to minimize any possible reaction. These children had 15 injections; none of them had a reaction, said study co-author Humaa Bhatti, DO, a pediatric resident at Metro Hospital, Cleveland.
“The severe reaction, I think, falls into a very rare category,” Siles commented. “While observation of these children with known allergies should be considered, our study would indicate that the presence of food allergies should not be considered a contraindication for vaccination.”
Sampson disclosed commercial financial relationships with Herbal Springs and Genentech.
Sicherer and other authors had no commercial disclosures. Siles and Bhatti had nothing to disclose.