Flu jabs & other seasonal vaccinations

A few weeks ago 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 Paediatrician and Immonologist, 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, now that the flu-season starts, 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 untreated or complex heart patients. So, like all people with medical conditions that put them at increased risk of complications from ‘flu, the vaccination is recommended for 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, to maintain protection, 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 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.

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.

There are a number of pneumococcal vaccines and in fact, since September 2006, 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.

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. And while 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 every 5 years because antibody levels decline over time, esp in functionally asplenic patients or these with impaired ability to respond to vaccines.

You may be surprised to know that there are over 90 serotypes of this bacteria! I’ve said there are a number of different pneumococcal vaccines; none of them protects against all pneumococcal serotypes. The conjugate vaccine in the standard immunisation schedule protects against seven common serotypes causing invasive disease in children. Newer vaccines with wider coverage are being developed all the time.

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 synthesised in a lab and not obtained by human blood donors. There is good evidence from large clinical trials that the RSV vaccine protects babies with chronic lung disease against severe RSV disease and reduces the longer term consequences RSV bronchiolitis such as worsened lung disease or wheezing. These babies receive a dose of RSV antibodies every month for the 5 months during the winter (RSV) season. But not all premature babies should get RSV vaccine, mainly those with ongoing lung disease. By the time children are over 2 years of age, they are less vulnerable to RSV infections and don’t need further doses.

There is much less evidence of benefit from the RSV vaccine for cardiac children and unfortunately it is unlikely that there will be new randomised controlled trials to inform us scientifically. So, in the absence of good evidence, expert advice is to consider RSV vaccine for babies less than 6 months of age with left to right shunts and haemodynamically significant congenital heart disease and/or pulmonary hypertension. The product licence does extend up to 2 years in this group of children as well but this scientific evidence of benefit as not strong as one would wish. Parents sometimes worry that RSV vaccine is restricted on the grounds of cost, but the issue here is more that whenever we make recommendations, we endeavour to ensure the benefits outweigh risks as far as it possible.

On the other hand, it’s worth acknowledging that parents sometimes worry about ‘overwhelming’ their children’s bodies with vaccines. This does not occur and we recommend vaccines where there is good evidence that providing protection by immunisation is safer for the child than catching the illness naturally.

TK: Our current policy on the RSV vaccine is to identify high risk patients, and recommend the vaccination only to those. Do you think this appropriate?

EM: Yes Thomas, best practice is to identify amongst your patients those with the severe cardiac problems I’ve outlined, because these are the cardiac babies at greatest risk of compromise from severe RSV bronchiolitis.

TK: Thank you very much for your help, Esse.