Thimerosal in pediatric practice

Mercury has no physiological function in the human body and is widely distributed in nature. It may be toxic by inhalation, ingestion or contact. Thimerosal is an organic salt of mercury used as an antiseptic and antifungal since 1928. Since the late 1990s, mercury began to be withdrawn from drugs and materials for clinical use. An effort has been made to remove thimerosal from vaccines as a precautionary principle, since there is no scientific evidence to substantiate that brain damage can be attributable to thimerosal. No connection has been found between its use and the risk of developing autism. In the Western World it is only currently used in very few vaccines in multidose containers, whereas all those included in Spanish Schedules, as well as in those commonly used for children outside them (pneumococcal and rotavirus), are free from thimerosal. However, the WHO has reiterated that vaccines containing thimerosal may still be used, especially in the Third World where, for logistical needs, multidose containers are used, as the real risk of illness and death by vaccianble diseases in those who do not get vaccinated is much higher than the hypothetical risk arising from their use. As with any medicine, there may be hypersensitivity reactions to thimerosal, usually local. Research efforts should be directed towards finding the real causes of neurological problems like autism instead of throwing doubts about the safety of vaccines.