The whooping cough vaccine contains mercury

The National Autistic Society said it had always "supported moves to ensure that mercury is not used" in vaccines.

But concern has been expressed over a new five-in-one jab that will include the whooping cough vaccine.

Patients' Association chairman Michael Summers questioned whether "proper trials had been conducted."

Autism link?

The move follows recent research in America that suggests a connection between the mercury used to preserve the whooping cough vaccine, and autism.

We are continually looking at ways to improve this programme as new, more effective products become available Health Minister John Hutton Medical notes: Autism

The Department of Health has always maintained there is no evidence of such a link.

But Health Minister John Hutton has confirmed that a five-in-one injection, containing vaccinations for diphtheria, tetanus, whooping cough, Hib and polio, will be introduced later in the year.

"We are continually looking at ways to improve this programme as new, more effective products become available," he said in a statement.

Doctors are also being told to switch from the live polio vaccine, currently given by mouth, to a "killed" vaccine injection to avoid rare cases of polio contamination, according to a report in The Daily Telegraph newspaper.

GP Richard Halverson told BBC News: "I welcome the fact that mercury is being withdrawn because it is toxic and should not be injected into babies full stop.

"Mercury is one of the most toxic elements on this planet. It has no business being ingested in any form by anyone, it serves no useful purpose, it is dangerous."

He also welcomed changes to the polio vaccine, saying it was "disgraceful" that the only cases of paralysis from polio in the UK in the last 15 years had been as a result of the vaccine.

Safety fears

But Mr Summers said that while the removal of mercury was "long overdue", patients would need reassurance about the new injection.

What we want to see is more choice, where the vaccines are designed around what is right for the individual child Jackie Fletcher Jabs

He said: "Perhaps next week the chief medical officer would explain to the public precisely how this has now come about and whether proper trials had been conducted with a view to establishing whether it is safe."

Jackie Fletcher, founder of support group Justice, Awareness and Basic Support (Jabs), said: "With five-in-one vaccines we would want to know what safety trials have taken place.

"How did they find out it was safe to do it in this combination?"

Increasing the combinations increased the potential for an adverse reaction, she said.

"What we want to see is more choice, where the vaccines are designed around what is right for the individual child."

Shadow health secretary Andrew Lansley said in a statement: "The way in which this has been announced leaves questions unanswered and further undermines confidence in the approval system for vaccinations.

"Removing mercury from the preparation of vaccines is clearly the right thing to do, but public concerns about combining vaccines need to be addressed."

Research

In June, it was announced that US researchers at Columbia University found autism-like damage in the brains of mice exposed to thiomersal, the preservative used in the whooping cough vaccine.

Despite other US and European studies finding no link between mercury and autism, the Columbia team said they found that mice exposed to thiomersal showed signs of changed behaviour, and brain abnormalities.

The animals had been bred to be vulnerable to developing disorders of the immune system.