News of the Day ... in Perspective
Maryland proposes to ban vaccines containing heavy metals
Maryland House Bill 86 would prevent the administration of any vaccine that contains any amount of a heavy metal to children under three or to pregnant women. [Presumably, this means an amount detectable by increasingly sensitive methods of analysis.]
A letter from the Institute for Vaccine Safety, Johns Hopkins Bloomberg School of Public Health, states that “several years ago, there was justified concern about the amounts of mercury-containing thimerosal preservatives used in the vaccines of that day.”
The manufacturing process for some DTaP (diphtheria tetanus acellular pertussis), hepatitis B, and influenza vaccines uses thimerosal. Manufacturers now extract the thimerosal prior to sale, reducing its concentration to 1/100th of its previous level: from 50 micrograms per dose to less than 0.5 mcg/dose.
In opposing HB 86, Professor and Director Neal Halsey, M.D., and coauthors state: “Potential danger due to mercury exposure in thimerosal is dose related. In reality, all of us are exposed to low levels of other mercury compounds in everyday food products. It is not possible to completely eliminate all exposure. The removal of thimerosal as a preservative from vaccines routinely administered to children has removed the theoretical risk that existed in 1999.”
The supply of thimerosal-reduced influenza vaccine would not be adequate to protect all children in an influenza pandemic, and reduced-thimerosal tetanus toxoid might not be adequate for all pregnant women who might need it, Halsey et al. write.