ST ALBANS parliamentary candidate Anne Main is calling on parents to be aware they have a choice of whooping cough vaccine after a study raised fears of a link to autism.

Questions have been hanging over the NHS' standard DTP jab, given to babies as young as eight weeks, and American research claims it increases the risk of autism six times as it uses a mercury-based preservative, thimerasol.

The DTP jab is no longer used in many other countries including the USA where multi-million pound lawsuits have been lodged against the manufacturer, Eli Lilly.

Tory hopeful Mrs Main says there is an alternative jab, GlaxoSmithKline's Infanrix, that does not contain thimerasol and is available on the NHS. She wrote a year ago to 13 St Albans GP surgeries asking about DTP, but not one has told her whether they offer Infanrix as an alternative.

She said: "It is vital that parents are fully informed."

Supporters of the DTP jab argue it is twice as effective as the alternative.

Opponents say the Government will not ditch DTP as it is nearly half the price of Infanrix and have also raised fears about side effects such as fevers. They say the mercury thimerasol contains can harm babies as they may not be able to excrete it.

But government experts on the Medicines and Healthcare Products Regulatory Agency reviewed thimerasol in September and found no evidence it did any harm.

A spokesman for St Albans and Harpenden Primary Care Trust, responsible for local GPs, said: "Vaccines with thimerasol have ethylmercury. The mercury that may be toxic in the diet or the environment is methylmercury. Both types are handled quite differently by the body.

"Ethylmercury is excreted quickly, even from tiny babies' bodies, and does not accumulate."