Thiomersal in vaccines

Organisations such as WHO, the US Environmental Protection Agency (EPA), the US Agency for Toxic Substances and Disease Registry, and the US Food and Drug Administration provide recommendations for safe exposure to methyl mercury in the diet. The risk from contamination of multidose vials would increase and lives would be put at risk from, for instance, toxic-shock syndrome. Because of its excellent track record of safety and efficacy as a vaccine preservative over many years, WHO will continue to recommend vaccines containing thiomersal.4 On balance, the known risk of morbidity and mortality from vaccine-preventable diseases and the dangers posed by contaminated multidose vaccine vials far outweigh any potential risk posed by thiomersal. Age Vaccines Hepatitis B (HB) vaccine Mercury dose (μg) Scheme A Scheme B Scheme A Scheme B Birth BCG, OPV 0 HB 1 12·5 6 weeks DTP 1, OPV 1, Hib 1 HB 2 HB 1 62·5 62·5 10 weeks DTP 2, OPV 2, Hib 2 HB 2 50 62·5 14 weeks DTP 3, OPV 3, Hib 3 HB 3 HB 3 62·5 62·5 Total 187·5 187·5 Table Mercury exposure from thiomersal in typical immunisation schedules