Author(s)

David Tran, Hazel Clothier, Jim P. Buttery, Nigel W. Crawford

Department of General Medicine, Royal Children’s Hospital (RCH), Melbourne, Australia;.
Department of Paediatrics, The University of Melbourne, Australia.
SAEFVIC, Murdoch Childrens Research Institute (MCRI), Melbourne, Australia.

BACKGROUND: The H1N1 pandemic in 2009 required a systematic coordinated response, which in Australia included a monovalent (H1N1/09) vaccine (Panvax^?). SAEFVIC (Surveillance of Adverse Events Following Vaccination In the Community) is the Victorian, Australia state-based vaccine safety unit. The aim of the study was to review SAEFVIC reports of adverse events following immunisations (AEFI) temporally associated with H1N1/09 vaccines [monovalent and Trivalent Influenza Vaccines (TIV)]. METHODS: 1) Analysis of AEFI related to H1N1/09 vaccines reported to SAEFVIC from September 2009 to December 2010; 2) Review of febrile convulsions (ICD-10 code R56.0), in children under 5 years of age presenting to the Royal Children’s Hospital (RCH) Melbourne, Emergency Department between 1 March-30 April 2010. The presentation details and immunisation history were clarified by a telephone interview. RESULTS: 1) There were 659 reports of 749 adverse events following H1N1 vaccines. Among the TIV group, Fluvax had the most AEFI reported, with 77 per 100,000 doses distributed. Serious AEFI temporally associated with H1N1/09 vaccines included: 3 deaths, 2 anaphylactic reactions, and 3 GuillainBarre Syndrome. There were 7 reports of drug administration error; 2) There were 179 presentations with fever and 67 reported febrile convulsions out of 11025 presentations (0.61%), 11 following H1N1 vaccines. Fluvax^? was associated with 55% (6/11) reports. The mean onset time of AEFI was 13.2 hours post vaccination, and there was complete resolution of symptoms in allcases with no significant morbidity. CONCLUSION: Consistent with other Australian states in 2010, there was a TIV brand specific [Fluvax^?] increase in febrile convulsions post vaccination. As a result this vaccine is no longer licensed for children <5 years of age. Comprehensive passive and active surveillance for AEFI needs to be incorporated into future pandemic planning.

H1N1; Influenza Vaccine; Adverse Events; SAEFVIC

Tran, D. , Clothier, H. , Buttery, J. and Crawford, N. (2012) Surveillance of adverse events following H1N1/09 influenza immunisation in Victoria, Australia. Natural Science, 4, 1065-1073. doi: 10.4236/ns.2012.412135.