Neomycin is an antibiotic that interferes with bacterial protein synthesis by binding primarily to the 30S subunit of bacterial ribosomes. Many vaccines contain trace amounts of neomycin to prevent bacterial contamination during the manufacturing process. As a topical medicament, neomycin elicits a high sensitization rate. According to the NACDG, neomycin is the third most prevalent allergen that often manifests as a delayed-type contact dermatitis.
There is little reason to believe that high sensitization rates to neomycin are attributable to vaccines. To date, no cases of local or generalized eczematous reactions to neomycin-containing vaccines have been reported. One case of anaphylaxis has been attributed to neomycin in a vaccine although the causal relationship is uncertain. Measles, mumps, rubella (as well as the MMR vaccine), varicella, and poliovirus vaccines contain ≤ 25 µg of neomycin per dose, an amount that typically does not elicit an allergic skin reaction. Although contact dermatitis from topical neomycin is common, it is generally not considered to be a contraindication to immunization with neomycin-containing vaccines.
Dermatitis. 2005;16(3):115-120. © 2005 American Contact Dermatitis Society
Cite this: Hypersensitivity Reactions to Vaccine Components - Medscape - Sep 01, 2005.