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Parents’ immunisation questions answered

Dr David Elliman and Dr Helen Bedford present useful answers to a selection of the many questions parents ask about vaccinations

Dr David Elliman and Dr Helen Bedford present useful answers to a selection of the many questions parents ask about vaccinations

An effective immunisation programme depends on highly organised services. At practice level, one individual should be made responsible for immunisation.

They should arrange appointments, place orders for supplies and ensure they are properly stored.

Recording of vaccines given is vitally important both in clinical notes and on the child's personal health record. The information should also be shared with the child health system.

I have read about concerns over safety of the MMR vaccine. Is there any reason to be worried?

In 1998 a paper was published suggesting autism and bowel problems were linked1. Many parents remembered their children's difficulties beginning soon after they had had MMR vaccine. The authors were very clear in stating: ‘We did not prove an association between MMR vaccine and the syndrome described.'

Subsequently, three of the authors have voiced their concerns that there may be a link and advised the use of separate antigens rather than combined MMR vaccine.

This view has received disproportionate publicity and understandably many parents and health professionals are confused and concerned about the safety of the combined vaccine.

Since publication of this paper, a significant body of research has failed to find any evidence for a link between MMR vaccine and autism or bowel disease2,3,4. Despite this, the uptake of MMR has been adversely affected with outbreaks of disease.

At the time of writing, uptake of the vaccine is 79% overall, and lower particularly in inner cities. There is evidence that measles is on the brink of becoming endemic again5,6.

My child is allergic to eggs – can he still have the MMR vaccine?

MMR vaccines in use in most countries contain small quantities of egg and so there has been concern about giving the vaccine to children who are allergic to egg for fear that they might have a serious reaction to it. But there is considerable experience of using the vaccine in such children without any serious adverse effects.

Therefore, most experts would advise that the vaccine should be given but it may be appropriate to give it in a hospital if there has been an anaphylactic reaction to egg. This is more to reassure the parents than because it is a medical necessity.

There is no good evidence that skin testing helps in these children.

I understand there is mercury in some vaccines – isn't this harmful?

Some vaccines have a mercury-containing preservative, thiomersal. This was often added because many vaccines were dispensed in multidose containers and it was important to prevent bacterial contamination.

In other vaccines it was part of the manufacturing process.

There are no safety limits for the injection of mercury, but there are some for its oral ingestion. However, these vary widely. In 1999, it was noted that if an infant was given all the recommended vaccines in the US programme, in the first six months, they would exceed one of these limits.

However, the amount would still be below many other thresholds including those set by WHO and the American FDA.

Bearing in mind the precautionary principle and the fact that, in many countries, routine infant vaccines are rarely dispensed in multidose containers, manufacturers were asked to move towards thiomersal-free vaccines.

In the UK, even if an infant had been given all the routine vaccines according to the schedule in operation until September 2004, the amount of mercury received would not even have exceeded the lowest of the recommended safety levels. All vaccines in the current routine childhood immunisation schedule are free of thiomersal.

Doesn't giving all these vaccines overload the immune system?

Some parents and complementary practitioners have suggested that giving a number of vaccines together may overload the immune system, making children susceptible to other infections, autoimmune disorders and atopy.

There is no scientific rationale behind this in that the immune system is constantly being bombarded by foreign antigens and its capacity is enormous7.

A number of studies have shown serious infections are no more common in children in the period immediately after they have been immunised.

There are a number of studies that show no association between atopy and immunisations8,9. It is more difficult to disprove a link with autoimmune disorders. However, there have been no convincing studies supporting a link.

Wouldn't it be better to delay giving the vaccines until the baby's immune system is stronger?

Almost all babies produce an adequate immune response to vaccines given at eight, 12 and 16 weeks, but the very premature may not develop protective antibody levels to hepatitis B and polysaccharide conjugate vaccines. Consideration should be given to checking antibody levels after they complete the course of primary immunisations. If anything, side-effects such as fever and sore injection sites are more common when the immunisations are delayed.

Diseases such as Haemophilus influenzae type b, pertussis, and meningococcal C are more prevalent in younger children. By delaying vaccines, infants are subjected to a double whammy.

They are more likely to have side-effects, and protection against major infectious diseases is not there when it is most needed.

Dr David Elliman is consultant in community child health, Great Ormond Street Hospital

Dr Helen Bedford is senior lecturer at the Institute of Child Health, London

This article is an extract from Practical Paediatric Problems in Primary Care published by Oxford University Press, edited by Mr Michael Bannon and Professor Yvonne Carter www.oup.co.uk ISBN 978-0-19-852922-4

MMR jab

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