SIR – I would like to refer readers to the Vaccine- Autism Court Document Every American Should Read by David Kirby at the Huffington Post (http://www.huffingtonpost .com/david-kirby/thevaccineautism- court- _b_88558.html) The thrust of this story is that the mercury preservative (thimerosal) in vaccines aggravates mitochondrial disease (mitochondria are vital tiny cellular organs) to the point where indications of autism become manifested.

So it is the mercury preservative that is in question, not the medical components designed to combat measles, mumps and rubella. More of a mercury/autism debate, than a MMR/autism one.

When I worked in a laboratory all the bells and whistles went off if a mercury thermometer was broken and a spill occurred. There have been a number of flaps worldwide concerning the levels of mercury in seafood. Let us not forget either the mercury in our filled dental cavities.

Mercury is a neurotoxin which attacks fundamental cellular functions. Please do not be surprised if the controversy hovering over any mercury-containing vaccines refuses to go away.

MARK MANNING, Kidderminster.