Anaphylaxis as an adverse event following immunisation in the UK and Ireland
- 1Children's Allergy Clinic, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- 2School of Clinical Sciences, University of Bristol, Bristol, UK
- 3Clinical Sciences and Vaccine Institute, St. George's, University of London, London, UK
- 4School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
- Correspondence to Dr Mich Lajeunesse, The Children's Allergy Clinic, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK;
- Received 21 October 2011
- Accepted 2 December 2011
- Published Online First 23 January 2012
Anaphylaxis is a rare adverse event following immunisation (AEFI) and unlikely to be detected in prelicensure vaccine trials. Previous retrospective studies have been hampered by the paucity of information available to passive reporting schemes. The aim of the present study was to estimate the incidence and clinical presentation of anaphylaxis as an AEFI using prospective active surveillance.
Methods Children under 16 in the UK and Ireland with suspected anaphylaxis as an AEFI were reported through the British Paediatric Surveillance Unit (BPSU) between September 2008 and October 2009. Paediatricians completed questionnaires on presentation, diagnosis, management and outcome.
Results A total of 7 out of 15 reports met criteria for anaphylaxis following immunisation. Four of the seven children reacted more than 30 min after administration of the vaccine. Six children required treatment with intramuscular adrenaline and intravenous fluids, but all made a full recovery. Denominators were not available for all vaccines so an overall incidence was not calculated, however the estimated incidence was 12.0 per 100 000 dose for single component measles vaccine and 1.4 cases per million doses for the bivalent human papilloma virus vaccine (Cervarix, GSK).
Conclusions Anaphylaxis remains a rare adverse event following immunisation. No cases were related to vaccines given as part of the ‘routine’ infant and preschool immunisation programme, despite over 5.5 million vaccines being delivered in this time period. Some children had delayed onset of symptoms and this should be considered when vaccinating those at higher risk of anaphylaxis.
Funding This study was funded by an unrestricted educational grant from Sanofi Pasteur MSD.
Competing interests MEL has received reimbursement to attend scientific meetings from GSK and Wyeth. PTH is an investigator for clinical trials conducted on behalf of St. George's, University of London, sponsored by vaccine manufacturers. Industry-sourced honoraria for consultancy are paid to an educational/administrative fund held by St. George's, University of London. AF undertakes clinical trials and related research, consultancy, lecturing and chairing for all the major vaccine manufacturers and has received reimbursement of travel, accommodation, registration and living expenses related to these activities. All honoraria and research funding are paid either to the University of Bristol or University Hospitals NHS Foundation Trust.
Ethics approval North Somerset and South Bristol National Research Ethics Service.
Provenance and peer review Not commissioned; externally peer reviewed.