Flu jabs & other seasonal vaccinations

It is anticipated that this year’s Flu vaccine will incorporate the H1N1 Swine Flu vaccine, in case there is a resurgance of that particular strain of the virus alongside seasonal Flu.

Thomas Krasemann, consultant Paediatric Cardiologist, was asked by Jo Wilson to comment on the seasonal vaccinations (“flu-jabs”). He works together with Esse Menson, Consultant in Paediatric Infectious Diseases and Immunologist, in the Kawasaki-clinic anyway. Therefore he took the opportunity to conduct an interview with her focused on the needs of the cardiac patients.

Thomas Krasemann (TK): Esse, after swine flu last year, I understand it’s been another difficult year with flu in children. Do you think that a flu jab should be recommended for all our heart-patients? I thought it might be wise for all the untreated ones, especially the blue patients. When is it best to be given? And do the children need to fear repeated injections?

Esse Menson (EM): Influenza (‘flu) causes a nasty but self-limiting illness in otherwise healthy people, but it can be severe with multiple complications in vulnerable groups such as those with untreated or complex heart patients. So, like all people with underlying medical conditions that put them at increased risk of complications from ‘flu, the vaccination is recommended for children with untreated or complex cardiac patients.

But it’s not a one-off vaccine, I’m afraid. ‘Flu viruses have the capacity to change their principle surface antigens so, a new seasonal vaccine is made that is predicted to protect against the strains that will be circulating. It is important vaccinate each year with vaccine against the currently prevalent strains.

It is best for patients to get their ‘flu jab before the ‘flu season starts because it takes 10-14 days to develop protective antibodies. The ‘flu season usually starts in November but can be early some years so we recommend vaccination in September or October.

But don’t worry – if children at risk haven’t yet had this year’s ‘flu jab, it’s not too late; when they do have it, the GP could book next year’s jab in advance. It’s a good idea to think of the ‘flu jab at the start of each school year.

Children can have flu jabs from 6 months of age and above. Children under 13 years need 2 doses in their first year of ‘flu vaccination, after that its just one dose a year. The ‘flu vaccine is inactivated and contains no live virus so it can’t cause the disease it protects against and it is generally tolerated very well. Your patients will be protected against influenza for about a year, and while they can still catch colds and mild flu-like illnesses during that time, these will be much less severe than ‘flu.

TK: There is also the vaccine against pneumococcal infection. For which patients do you think this is indicated? Is this a “seasonal” disease as well? As far as I remember such an infection can occur all over the year, but please refresh my memory.

EM: You’re right Thomas, infections caused by pneumococcus (Streptococcus pneumoniae) are not seasonal. This bacteria causes ear, chest and bloodstream infections and even meningitis. The cardiac patients who are particularly at risk are those who have no functioning spleen – as the spleen is important in protecting the body against disease from this type of bacterium – and children with cardiac conditions assoc with immunodeficiency.

You may be surprised to know that there are over 90 serotypes of this bacteria! Vaccination aims to protect against the common serotypes causing invasive disease in children.

There are a number of pneumococcal vaccines and in fact, since September 2006, the conjugate pneumococcal vaccination is officially recommended as part of the standard childhood immunisation schedule because pneumococcus can cause serious invasive disease in any child. Doses are given to infants at 2, 4 and 13 months of age as standard for long-term protection. Even better news, a newer conjugate pneumococcal vaccine was introduced in 2010 which protects against 13 serotypes of pneumococcus instead of 7 serotypes. This extended spectrum vaccine will prevent even more severe pneumococcal disease.

Do check that all infants with congenital heart disease have not missed any doses.  Also, older children with congenital heart disease should receive a pneumococcal vaccine if they have not received it. ‘Cardiac kids’ should also have a ‘top-up’ dose of the 13-valent vaccine for extended protection.

Other healthy children don’t need any more doses after infancy, the current recommendation is for high risk groups such as cardiac patients to have a booster dose of a different 23-valent pneumococcal vaccine which clearly provides even more extended coverage but cant be used in those under 2 years of age because the infant immune system is too immature to respond to it. Such a schedule provides the best protection against pneumococcal diseases and it is necessary because antibody levels decline over time, esp in functionally asplenic patients or these with impaired ability to respond to vaccines.

Again, pneumococcal vaccines do not contain any live organisms and are tolerated very well.

TK: We receive many questions about the RSV (respiratory syncitial virus) vaccine. This is a vaccine that needs to be given repeatedly, and it does not seem to prevent the infection in 100%. I know that preterm babies are considered to be at a higher risk, but what about our cardiac patients?

EM: There is understandably concern about RSV infection because it is a major cause of respiratory infection and breathing difficulties in babies and young infants. In the young the illness caused is called bronchiolitis; in older children and adults, the same virus causes a mild illness like a nasty cold and doesn’t affect the lungs much. A vaccine does exist which can give vulnerable young babies some protection against RSV bronchiolitis but a large number of other viruses cause a similar illness and these are not protected against by the vaccine so protection against bronchiolitis is certainly not 100%.

The RSV vaccine is a ‘passive’ immunisation; that means it gives the baby doses of antibodies against RSV but rather than stimulating the body to produce antibodies itself like most other vaccines you’ll be familiar with.  In this case, the antibodies are synthesized in a lab and not obtained by human blood donors. There is evidence from clinical trials that the RSV vaccine protects premature babies with chronic lung disease against severe RSV disease and reduces the longer term consequences RSV bronchiolitis such as worsened lung disease or wheezing. Recent revision of national guidance from the Joint Committee on Vaccination and Immunisation (2101) tells us to give RSV vaccine to cardiac babies only if they were also premature and have haemodynamically significant, acyanotic heart disease. The age at which this should continue to varies according to the degree of prematurity but is maximally to age 6 months for the most preterm, eligible cardiac babies.

So Thomas, best practice is to identify amongst your patients those babies who meet the JCVI 2010 criteria and then ensure the start getting RSV vaccine doses before the start of the RSV season – the beginning of October each year.

TK: On the other hand Esse, some parents are concerned that their child’s cardiac condition is a reason to delay vaccinations. Do you think this appropriate?

EM: It’s not hard to appreciate that parents of a sick child with sever heart disease will have concerns that ‘routine’ interventions that are recommended for healthy children might make their child sick. Parents sometimes worry about ‘overwhelming’ their children’s bodies with vaccines. This does not occur and in fact these children need protection against vaccine-preventable diseases a whole lot more than healthy children do. Also there is good evidence that providing protection by immunisation is safer for the child than catching the illness naturally. So long as a child with severe heart disease does not have an acute infection or fever, non-live vaccines are all safe. Live vaccines such as MMR and BCG (and also the chickenpox vaccine, although this is not routine in the UK schedule) are safe for most cardiac children too, unless there is concern about that child’s immune system. If there is concern, a paediatric immunology specialist should see the parents and child first.