<prompt> Which of the following statements about vaccines is falseThiornersal is preservative in DPT vaccineMagnesium chloride is stabilizer used in OPVKanamycin is preservative in measlesNeomycin is preservative in BCG vaccine  <response>: Neomycin is preservative in BCG vaccine Ref: see belowRepeat.from Nov 08 Neomycin is used as a preservative in Measles, mumps, rubella as well as the MMR vaccine, varicella, and poliovirus vaccines but not in BCG. About option a i.e Thiomersal is preservative in DPT vaccine Ref: Thiomersal is a mercury-based substance that has been used widely in vaccines for over 60 years as a preservative to prevent bacterial and fungal contamination, paicularly in multi-dose ls. It is used as preservative in following vaccines- DPT, Hib, Hepatitis A B and influenza vaccines. Recently, concerns have been raised and much debate is done over the safety of thiomersal in vaccines. It is said that it being mercury based compound it can cause neurotoxicity. It is being related to autism in children. However The World Health Organizations Global Advisory Committee on Vaccine Safety GACVS has concluded in November 2002 that there is no evidence of toxicity in infants, children or adults exposed to thiomersal in vaccines. Still thiomersal is being replaced or reduced in vaccines. 