Pandemic A/H1N1 2009 influenza vaccination, preceding infections and clinical findings in UK children with Guillain-Barré syndrome

Objective: To record clinical findings in all new cases of Guillain-Barré syndrome (GBS) or Fisher syndrome (FS) in UK children in the 2 years following September 2009 and determine the proportion temporally associated with recent infections, pandemic H1N1 (2009) strain influenza vaccination or seasonal influenza vaccination. Design: A prospective UK-wide epidemiological study using the British Paediatric Surveillance Unit system. Patients: Children aged 16 years or less meeting the Brighton Collaboration criteria for GBS or FS. Results: 112 children with GBS (66 boys and 46 girls) and 3 boys with FS were identified in 2 years. All but one recovered sufficiently to go home. The annual UK incidence rate of GBS in patients less than 15 years old was 0.45/100 000, similar to other countries. There was evidence of infection in the 3 months preceding onset in 92/112 GBS and 3/3 FS cases. Of those living in England, 7 cases received pandemic A/H1N1 2009 influenza vaccination before GBS symptom onset (3/7 were within 6 months including 1 within 3 months); 2 children received 2010/2011 seasonal influenza vaccination within 6 months of GBS onset. The numbers vaccinated were not significantly greater than expected by chance. Conclusions: The outcome for childhood GBS and FS after 6 months was better than reported in adults. Most UK GBS and FS cases had infections in the preceding 3 months. When considering the children living in England, there was no significantly increased risk of GBS after pandemic A/H1N1 2009 influenza vaccination or 2010/2011 seasonal influenza vaccination.