Neomycin

Anti-bacterial for Influenza, measles, mjmps, rubella, MMR, polio, rabies, vaccinai and varicella (chickenpox) vaccines

This is an antibacterial drug that is poorly absorbed when taken by mouth.  It is combined with enteric coated erythromycin to suppress gastrointestinal (GI) bacteria (your positive bacteria that is essential in your gut), before surgery to avoid infection.  Neomycin is used to treat hepatic coma in cases of liver failure and is included in some antibiotic products used to treat infections of the eyes, ears, or skin

http://www.gnc.com/health_notes/Drugs/Neomycin.htm#Intorductory

of contaminants which are not antigens and have been introduced in the preparation of the vaccine (like, e.g., substances used in cell cultures on which the vaccine virus grows, or insufficiently purified bacteriological antigens), or in-vivo replications of the viral or bacterial organisms. Hypersensitivity reactions may conceivably be due to additives to the vaccine; like, for example, neomycin in the MMR-vaccine or the mercury contained in Thimerosal, a preservative used in the DTP-vaccine. [25].

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