FEARS that thousands of youngsters are at risk of meningitis after being given sub-standard injections were last night played down by doctors and health chiefs.

Babies are vaccinated at two, three and four months against Hib, a disease which causes a range of serious illnesses including meningitis and pneumonia.

But a shortage of the traditional vaccine, DTwP/Hib led doctors across the country to use a replacement supply, DTaP/Hib.

Now many parents have received letters calling their children back in for extra doses of the original vaccine.

In the meantime, routine monitoring carried out by health professionals has revealed that the number of cases of Hib is on the rise, last year totalling 122.

Middlesbrough GP Dr John Canning, said details of a national "catch-up" campaign offering an extra dose of the original vaccine had been announced in February.

In Middlesbrough alone 8,500 children are receiving the extra dose and immunisations started last month.

Dr Canning said: "The alternative is not an inferior vaccine and it has its advantages as opposed to the original - it is a matter of balancing things out."

He said: "There is a general caution about immunisations among the public in this country.

"But, certainly on this issue, I have not heard any complaints or questions from parents."

A spokeswoman for Middlesbrough Primary Care Trust said: "The reasons for this small increase in cases in Hib in the last two or three years are very complex and in part may relate to a change of vaccine.

"The important message to all parents is that they take their child along as part of this national campaign to have their child protected against this disease."