The move, announced by Department of Health on Tuesday, follows an increase in cases of the disease, which can cause a number of serious illnesses in children, including a form of meningitis.

Our advanced disease surveillance programme has identified a small but significant increase in cases of Hib recently.   Sir Liam Donaldson

The new jab will be offered to all children aged between six months and four years on 1 April 2003.

It was recommended by experts from the Joint Committee on Vaccination and Immunisation (JCVI).

Successful campaign

Since 1992, all children have been routinely immunised at two, three and four months against the disease.

This campaign has been a success with cases of Hib falling dramatically, almost disappearing in young children.

However, there has been a very small but gradual increase in the number of cases of Hib disease reported since 1998.

Although this number is small (122 cases in 2002) and much lower than the levels seen before the introduction of Hib vaccine (around 800 every year) it is still significant.

The Chief Medical Officer, Sir Liam Donaldson, has written to GPs and other health professionals informing them of the planned campaign which it is anticipated will start in Spring of this year.

Sir Liam said: "Vaccinating children against Hib disease has proved very successful in cutting rates of this disease.

"Over the last ten years this vaccination has prevented about 7,300 cases of Hib disease and approximately 270 deaths in children aged under four.

"However, our advanced disease surveillance programme has identified a small but significant increase in cases of Hib recently.

"In order to halt and reverse this increase, a Hib vaccination catch-up campaign is being planned."

Infection

Julia Warren, of the Meningitis Research Foundation, told BBC News Online: "Anything that can continue to keep cases of Hib disease down we would certainly welcome - we don't want to see young children getting meningitis."

A spokesperson for the Meningitis Trust urged parents to take up the offer of the one-off vaccine if their children were of the appropriate age.

Parents will be invited to bring their children for immunisation in the same way as other childhood vaccines.

Hib is the term commonly used to describe a disease caused by the bacteria Haemophilus influenzae type b.

As well as meningitis, it can cause infection in joints, pneumonia and epiglottitis (causing swelling of part of the windpipe causing noisy, painful breathing and even blockage of the airway).

The disease is most common in children under four years of age (with the exception of children aged under 3 months where it is rare).