Children under five are only routinely vaccinated against seasonal flu if they are in designated ‘risk groups’ because they have chronic asthma Photo: ALAMY
GPs have been told not to use a particular flu jab on 110,000 children under five after it was linked with a tenfold increase in fits, it can be revealed.
By Rebecca Smith, Medical Editor
Doctors should stock alternative vaccines for under fives who are due to have the seasonal flu vaccine this winter, a letter from the head of immunisation at the Department of Health has said.
The action is being taken as rate of convulsions caused by high fever among children in Australia given the jab was ten times higher than normal.
Up to one in 100 children given the jab, made in Australia by CSL and marketed in the UK by Pfizer, suffered febrile convulsions in the following hours and days.
It is not known what is causing the problem and no other flu vaccines have been linked to an increased risk of fits. Adults given the vaccine do not appear to have been affected.
Children under five are only routinely vaccinated against seasonal flu if they are in designated ‘risk groups’ because they have chronic asthma, have been admitted to hospital with a respiratory infection previously or have other long-term conditions which means they would be particularly badly affected if they caught flu.
Seasonal flu vaccines contain three strains which have been identified by the World Health Organisation as the most common in circulation that year. This year the vaccines contain the pandemic strain H1N1.
The letter to all GPs from Prof David Salisbury, said: “Epidemiological information from Australia indicates that there has been a higher than expected increase in febrile convulsions in children related to the use of Fluvax (manufactured by CSL).
“This is the same product that will be marketed in the UK by Pfizer as Enzira and generic influenza vaccine for the 2010/11 influenza vaccination season.
“Evidence from Australia suggests a rate of febrile convulsions of about one per 100 for children who were vaccinated with Fluvax. This increased risk appears to be a product specific reaction and evidence from Australia of vaccination with other products has so far not indicated a similar level of risk.
“It is important that children over six months of age who are in clinical risk groups receive influenza vaccination. Given the availability of other influenza vaccine products, you should avoid offering Enzira or CSL Biotherapies generic influenza vaccine marketed by Pfizer to children aged under five years.”
He added that the medicines regulator will be monitoring the situation.
Febrile convulsions affect around one in 20 children and are normally caused by an infection. The body reacts to the high fever with the child losing consciousness and their legs and arms jerk. They may go pale or turn blue briefly and after a few minutes the shaking normally stops.
The attacks can be very frightening for parents and children are usually admitted to hospital after the first convulsion to establish the cause. Some children are particularly prone to them but they are not normally dangerous.
In Australia, which is in its winter, stopped vaccinating all children under five when the increased rate of convulsions was found. It has since restarted vaccinating with other products.
A spokesman for Pfizer said: “The cause of the unexpected increased frequency of febrile convulsions remains unknown and investigations continue. Pfizer and CSL are working closely with regulatory authorities, health agencies and distribution partners to determine the most appropriate way to provide influenza vaccine for the Northern Hemisphere 2010/2011 influenza season.
“While, Pfizer supports the current precautionary approach to the use of our influenza vaccine in children under five years of age, it should be noted that the vast majority of patients in the UK receiving the influenza vaccine are adults, and febrile convulsions are not seen in the adult population.
“In addition, there is no evidence that the vaccine poses any increased risks to other groups, including pregnant women and those aged over 65.
“Pfizer and CSL are committed to ensuring the quality and safety our products. Pfizer is in ongoing dialogue with the Department of Health to help ensure the successful implementation of the 2010/11 Flu immunisation programme.”
A spokesman for the Department of Health said: “As part of the Australian flu vaccination programme, a number of children were given a brand of flu vaccine known as Enzira (Fluvax in Australia). A small proportion of these children, aged under 5, had fits after they had this vaccine.
“The vaccine is also marketed in the UK as CSL Biotherapies generic influenza vaccine. It contains three strains of the flu virus that experts predict are most likely to be around this winter including swine flu (H1N1).
“We are asking GPs in the UK to avoid offering this vaccine to the under 5s in the coming flu season, there are several other vaccines available that are suitable for this age group. There is currently no indication that the vaccine poses any increased risks to other groups.
“Having the flu jab remains the best protection against flu and we recommend that people get vaccinated when they’re offered it in the autumn.”