Flu vaccine unlikely to trigger reaction in children with egg allergy and asthma

Evidence suggests that children and young people are the main spreaders of influenza infection. In 2012, the UK Department of Health therefore recommended annual vaccination of those aged 2-16 years of age with live attenuated influenza vaccine (LAIV) as part of the NHS childhood vaccination programme.

LAIV is a nasal spray vaccine developed specifically for young people, but there are limited safety data for its use in young people with egg allergy and/or asthma. Some guidelines recommend against using LAIV in children under 5 years with a history of recurrent wheeze or asthma.

But this means that thousands of young people are not protected and can spread the disease to others, so a team of researchers set out to assess the safety of giving LAIV to those with egg allergy.

A total of 779 young people (aged 2-18 years) with egg allergy were recruited from 30 UK allergy centres and immunised with LAIV. Some 315 (40%) had experienced an allergic reaction to egg in the past 12 months, 270 (35%) had experienced previous anaphylaxis to egg, and 445 (57%) had doctor diagnosed asthma or recurrent wheeze.

Participants were observed for at least 30 minutes after vaccination and followed-up by telephone 72 hours later. Those with a history of recurrent wheeze or asthma underwent further follow-up four weeks later.

No systemic allergic reactions occurred within two hours of vaccination. Nine participants (1.2%) experienced mild symptoms including a skin rash, sneezing, itchiness and a blocked or runny nose, suggesting a local allergic reaction.

Delayed events potentially due to the vaccine were reported in 221 participants, but no participants were admitted to hospital and no increase in lower respiratory tract symptoms occurred in the four weeks after vaccination (assessed with an asthma control test).

This study confirms our previous findings that LAIV is unlikely to trigger a systemic allergic reaction in young people with egg allergy, say the authors.

It also provides evidence to support the revised Department of Health guidance for the 2015/16 season that, with the exception of children "with severe anaphylaxis to egg which has previously required intensive care, children with an egg allergy can be safely vaccinated with Fluenz Tetra® in any setting (including primary care and schools)."

As with all settings providing vaccination, they stress that facilities should be available and staff trained to recognise and treat anaphylaxis.

Furthermore, they conclude that the vaccine "is appropriate for use in children at risk of wheeze, in whom symptoms are well controlled and with no evidence of active wheezing in the 72 hours before immunisation."