‘Flu vaccine and the paediatrician

In a guest blog anticipating the start of 'flu season, RCPCH immunisation experts, Professor Helen Bedford and Dr David Elliman share their thoughts on improving rates of vaccination among children, some misconceptions around the flu vaccination and the role of the paediatrician.

Why is 'flu vaccination an important topic for the paediatrician? Isn’t this something GPs deal with? In a ‘normal’ year, three in every thousand (about a thousand children) otherwise well children under six months old are admitted to hospital with influenza. The rates of admission are half this in children aged 6 months to 4 years and 10 per 100,000 older children are admitted. While having a chronic medical condition makes little difference to admission rates in children under 5 years old, it increases the risk five fold in older children. Importantly, the presence of almost any chronic medical condition, including learning disorders, in those admitted to hospital results in an average forty fold risk of dying1.

Super spreaders

Infected children, especially younger children, are an abundant source of virus and are more than willing to share it with anyone with whom they come into contact. This may include their grandparents and other vulnerable members of the population. Hence their reputation as ‘super spreaders’!

This makes children an important group of recipients for influenza vaccine. For many years, at-risk children, over six months old, should have been offered an inactivated trivalent vaccine. Since 2013-14, a programme of immunising children aged 2 and upwards has been rolled out.

This year, all at-risk children older than six months and all other children from 2 years old to school year 5 should be offered a ‘flu vaccine. Children under 2 years old are offered an inactivated quadrivalent injected vaccine, while those aged 2 years to 17 years old are offered the nasally administered live attenuated quadrivalent vaccine (LAIV). LAIV is the vaccine of choice as it is the most effective vaccine in this age group; however, it is not licensed for children younger than two years2.

Data from the UK have shown that the LAIV has a moderate effectiveness (50-60%) which varies year on year. For example, in 2015-16 the vaccine was 81% effective against the influenza B strain3. In addition, in areas where the vaccine has been offered to all primary or secondary school children, there has been significantly less influenza like illness in the general population.

Poor uptake

Unfortunately, the uptake in children is poor. For children with chronic disorders the uptake was 21% in those aged 6 months to under 2 year olds and 45% in those aged 2 years to under 16 years4. Since almost all of these children will be seeing a paediatrician, you are uniquely placed to advise parents.

As most chronic disorders (including diabetes, heart, liver, respiratory, neurological disease, etc.) are an indication for the vaccine you can explain to a parent or young person why it is particularly important. Often children with complex disorders miss out on immunisation because the specialist forgets and the GP is unsure about contraindications, or each thinks the other is responsible. There are few contraindications to the vaccine; however, all currently available vaccines contain egg and a full risk analysis should be taken before immunising a child who has had an anaphylactic reaction to egg. Egg allergy without anaphylaxis is not a contraindication. LAIV should not be given to those who are severely immunocompromised, have severe asthma or are taking salicylates. The inactivated vaccine should be offered instead5.

A concern often voiced is that the vaccine itself may cause 'flu. This is not possible. People may develop 'flu after the vaccination, but this will be because it has been ineffective, not because it has caused ‘flu. Also, in some cases, the mild adverse events following the vaccine, such as fever and malaise may be confused with ‘flu.

Making every contact count

Ideally, any eligible children or young people should be offered immunisation on the spot. Second best is to communicate directly with primary care about the need for individual children to be offered the vaccine. Paediatricians seeing children with allergic disorders can ensure that GPs are properly informed about the suitability of such children for this and other vaccines.

This also acts as an opportunity to review a patient’s vaccine status more generally. We have recently had large outbreaks of measles partly as a result of many older teens who never had MMR vaccine as toddlers because of their parents’ concerns over the safety of the vaccine – and there are still avoidable deaths from meningococcal disease in adolescents.

But importantly, it is not only your patient that needs immunising - you and your colleagues should have it, too. This will prevent you being the source of infection for your vulnerable patients. Last year 71.7% of doctors and only 65.2% nurses had the vaccine6. Although an improvement than in previous years, room for improvement remains.