Tuesday, 2 March 2004

Questions (251)

John Gormley

Question:

331 Mr. Gormley asked the Minister for Health and Children his views on the use of mercury in vaccinations for children; and if he will make a statement on the matter. [6973/04]

View answer

Written answers (Question to Minister for Health and Children)

The Irish Medicines Board, which has statutory responsibility for licensing all pharmaceutical products for use in Ireland, has provided the following information in relation to thiomersal. Thiomersal is a mercury-containing preservative used in vaccines to prevent bacterial contamination. There has been no thiomersal in the vaccines used in the national primary childhood immunisation programme, which covers children from birth to the age of two, since 1996; this includes BCG, DTaP — diphtheria, tetanus, acellular pertussis and inactivated polio vaccine — oral polio, Hib and MMR.

The IMB has advised that thiomersal is present in the newer four-in-one and five-in-one vaccines, Tetravac and Pentavac, in trace amounts. The trace amounts are equivalent to values below the limit of detection, corresponding to less than 18 nanograms per vaccine dose. According to the IMB, these trace amounts of mercury have no biological effect and such products should be considered equivalent to thiomersal-free products. The IMB has further clarified that, as with any agent, hypersensitivity reactions can occur in sensitised individuals despite this very low concentration; however, previous experience with Pentavac and Tetravac in other countries has shown no evidence of any such reactions having occurred due to thiomersal. TheLancet published an article in 2003 which suggests that the level of thiomersal in vaccines given in infancy does not appear to elevate blood concentrations of mercury above safe levels in infants. The IMB has published articles on the subject of thiomersal in its drug safety newsletter; these articles are available at www.imb.ie.