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Volume 404: debated on Thursday 8 May 2003

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To ask the Secretary of State for Health what assessment he has made of the link between mercury in vaccines given to babies and (a)autism and (b) heart disease. [109928]

Thiomersal is an ethylmercury-containing compound that has played an important role either as a preservative or in the initial stages of the manufacture of some vaccines for over 60 years. As with all medicinal products, the Medicines and Healthcare Products RegulatoryAgency (MHRA) and the Committee on Safety of Medicines (CSM) keep the safety of thiomersal-containing vaccines under continual review. The CSM has reviewed the safety, including postulated neurological adverse effects, of thiomersal-containing vaccines on a number of occasions.CSM has recently reviewed two UK-based epidemiological studies that have provided reassuring results regarding the safety of thiomersal in vaccines, in relation to neurodevelopmental disorders. One of these studies, which used the United Kingdom's general practice research database (GPRD), specifically investigated whether there is any link between early thiomersal exposure through immunisation and autism. This study concluded that administration of thiomersal through childhood immunisation in the UK was not associated with an increased risk of developing a neurological developmental disability, including autism.

The CSM has carefully considered the results of a recent study, by Geier and Geier, that suggests an association between thiomersal exposure through the United States childhood immunisation schedule and the development of autism and heart disease. CSM advised that the methodology in this publication had been inadequately described and that the authors conclusions regarding the association between thiomersal in vaccines and autism, speech disorders and heart disease are not justified. The CSM has advised that, with the exception of allergic reactions such as redness and swelling at the injection site, there is no evidence of harm from thiomersal contained in vaccines. The CSM has advised that the benefits of immunisation with thiomersal-containing vaccines outweigh any potential risks of vaccination.

To ask the Secretary of State for Health what plans he has to phase out the use of mercury in vaccines given to babies. [109929]

The only vaccines used in the United Kingdom routine childhood immunisation programme that contain a mercury compound are diphtheria, tetanus and whole cell pertussis and diphtheria and tetanus vaccines. The mercury is present as ethylmercury in the excipient thiomersal.While there is no evidence of harm caused by thiomersal in vaccines, the European Medicines Evaluation Agency recommended that it would be prudent to promote the use of vaccines without thiomersal as a precautionary measure. The Committee on Safety of Medicines has endorsed this recommendation and continues to do so. Manufacturers are actively developing research programmes to eliminate, substitute or reduce thiomersal in vaccines following these recommendations. This may take time because manufacturers are required to ensure that the reduction, replacement or elimination of thiomersal does not affect the safety, quality and efficacy of the final vaccine.To date, a number of UK licensed vaccines have had levels of thiomersal reduced or removed completely from the manufacture of the component antigens or from the final vaccine. These developments are regularly reviewed and on 1 April 2003, a letter was sent from the Medicines and Healthcare products Regulatory Agency to UK vaccine marketing authorisation holders, asking for an update on progress in reducing or removing thiomersal from vaccines.