Research Questions Infection Risk from Allergy Immunotherapy

Infection concerns regarding allergy immunotherapy sparked by a recent outbreak of meningitis caused by contaminated spinal injections.

A new study found there was no evidence of infections linked to the administration of allergy immunotherapy, despite recent concerns over the sterility of allergy shots.

A recent outbreak of meningitis attributed to contaminated spinal injections may have fueled proposed changes from the US Pharmacopeia (USP), according to a study published by Journal of Allergy and Clinical Immunology.

This change places allergen extracts into the same category as compounds injected into the circulatory system or cerebrospinal fluid. The current USP standards place these treatments into separate categories due to a relatively low infectious risk.

Independent allergy practices are likely to use the same sterile techniques used in hospitals, the study reported.

Researchers analyzed data from 3242 patients through the Research Patient Data Registry of Partners Healthcare from 2005 to 2015 in regards to allergen immunotherapy (AIT).

It was found that there were 86 patients treated for an infection during that time, however, the infections were not at the injection site and were not caused by AIT, according to the study.

"Our analysis of 10 years of data from large allergy practices at Massachusetts General Hospital and Brigham and Women's Hospital -- covering approximately 135,000 individual injections administered to about 3250 patients -- finds no incidence of infection related to those injections," researcher Aidan Long, MD, said in a press release. "This confirms that the sterile practices used in the preparation of allergy shots at our hospitals and at most clinical allergy practices do not pose an infectious risk for patients."

The researchers plan to present their study to the USP in order to continue the discussion.

“While it would be technically possible for hospital pharmacies to meet the proposed USP guidelines, doing so would require significantly more manpower, space and work,” Dr. Long said. “It is unlikely that any individual allergy practice not allied to a pharmacy would ever be able to meet the specifications, and given the current reimbursement rates, the additional costs would not be feasible for any active allergist inside or outside a hospital. The net effect would be the disappearance of subcutaneous allergen immunotherapy."