Dubé et al. BMC Public Health 2011, 11:128 http://www.biomedcentral.com/1471-2458/11/128 intention to receive the pandemic vaccine [37,38]. Inten- tion to be vaccinated against A(H1N1) pandemic influ- enza was also higher than vaccine uptake against seasonal influenza among healthcare workers usually reported in Canadian studies [39,40], which was esti- mated at 64% in 2006 [41]. In our study, a significant proportion of paediatricians who disagreed with the use- fulness to protect children with the seasonal influenza vaccine did not intended to recommend the A(H1N1) vaccine to their patients. However, results obtained by MCA should be interpreted with precautions as only 13.6% of the variability is summarized by the first and second principal components. This is principally due to the uneven distribution of response levels. Our study has several limitations. First, the study wasn’t initially designed for a “before-after” analysis. The increase in the willingness to be vaccinated against A (H1N1) pandemic influenza observed among paediatri- cians may result from a response bias of respondents having more doubts about pandemic vaccination before the vaccination campaign actually started. Nonetheless, respondents’ demographic and professionals characteris- tics as well as their attitudes toward vaccination in gen- eral were very similar, thus suggesting the two subsets of participants were comparable. Second, the dichotomi- zation of the dependant variable ("strongly agree” and “agree” versus all others) was a conservative choice and physicians who answered “somewhat agree” were con- sidered as having a neutral opinion, not a positive one. Third, the repartition of the answers to the dependant variable in the subset of data collected after the begin- ning of the vaccination campaign did not allow us to perform two multivariate analysis for the two subset. However, the model was adjusted to take into consid- eration the time period when the paediatricians com- pleted the survey (before or after the initiation of the campaign). Finally, the response rate was 50% and a non-participation bias cannot be excluded. However, the response rate remains satisfactory for a mail-based sur- vey with physicians [42-44]. In addition, socio-demo- graphic characteristics of respondents are comparable to those reported in other surveys conducted among Cana- dian paediatricians [42,45]. Socio-professional character- istics of respondents also allow us to suppose a good representativeness. Results of this study indicated a high level of paedia- tricians willingness to be vaccinated against A(H1N1) and to recommend the vaccine to their patients. Lack of knowledge on A(H1N1) vaccine, belief that A(H1N1) was not a severe disease as well as concerns over A (H1N1) vaccine safety and usefulness were barriers to paediatricians’ intention to recommend it. This is con- sistent with barriers to seasonal influenza vaccination among healthcare workers reported in the literature Page 8 of 9 [31,46,47]. Public health interventions to promote seaso- nal influenza vaccination among healthcare workers should include the delivery of evidence-based informa- tion regarding influenza vaccines’ safety, efficacy and usefulness. Educational campaigns should also stress out the threat posed by seasonal influenza to healthcare workers and the patients. Conclusion In summary, the results show the important increases in physicians’ level of confidence about A(H1N1) vaccine safety and immunogenicity and their willingness to recommend this vaccine during the first months of the campaign. More than 40% of all Canadians aged 12 years or older received at least one dose of the A(H1N1) vac- cine during the vaccination campaign [48]. In the pro- vince of Quebec, Canada, almost 80% of the children aged between 6 months and 5 years were vaccinated against A(H1N1) influenza [49]. Paediatricians’ support of the vaccination campaign and their recommendations were surely one of the key components of such a success. Acknowledgements We thank all participants as well as the Canadian Association for Immunization Research and Evaluation (CAIRE) and the Canadian Paediatric Society for their collaboration in this study. Author details 1Institut National de Santé publique du Québec, 2400 d’Estimauville, Québec, Canada. 2Centre de recherche du CHUL-CHUQ, Centre Hospitalier de l’Université Laval, 2705 Blv Laurier, Québec, Canada. 3University of British Columbia, 229 West mall, Vancouver, British Columbia, Canada. 4Canadian Center for Vaccinology, Health Centre, Clinical Trials Research Center, 5850/ 5980 University avenue, Halifax, Nova Scotia, Canada. 5Kingston, Frontenac and Lennox & Addington Public health Unit, 221 Portsmouth avenue, Kingston, Ontario, Canada. Authors’ contributions All authors except FD have been involved in the design of the study. ED and FD have drafted the manuscript. FD performed the statistical analysis. All authors have read and approved the final version of the manuscript. Competing interests This study was financially supported by the Quebec Ministry of Health and Social Services and by an unrestricted grant from GlaxoSmithKline. 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