Open Access Highly Accessed Research article

How has the flu virus infected the Web? 2010 influenza and vaccine information available on the Internet

Loredana Covolo1, Silvia Mascaretti2, Anna Caruana2, Grazia Orizio3, Luigi Caimi4 and Umberto Gelatti1*

Author Affiliations

1 Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Viale Europa 11, 25123, Brescia, Italy

2 Post-graduate School of Public Health - University of Brescia, Viale Europa 11, 25123, Brescia, Italy

3 Department of Medical Prevention - Brescia Local Health Authority, Viale Duca degli Abruzzi 15, 25124, Brescia, Italy

4 “Quality and Technology Assessment, Governance and Communication Strategies in Health Systems”, Study and Research Centre - University of Brescia, Viale Europa 11, 25123, Brescia, Italy

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BMC Public Health 2013, 13:83  doi:10.1186/1471-2458-13-83

Published: 29 January 2013



The 2009–10 influenza pandemic was a major public health concern. Vaccination was recommended by the health authorities, but compliance was not optimal and perception of the presumed associated risks was high among the public. The Internet is increasingly being used as a source of health information and advice. The aim of the study was to investigate the characteristics of websites providing information about flu vaccine and the quality of the information provided.


Website selection was performed in autumn 2010 by entering eight keywords in two of the most commonly used search engines ( and The first three result pages were analysed for each search, giving a total of 480 occurrences. Page rank was evaluated to assess visibility. Websites based on Web 2.0 philosophy, websites merely displaying popular news/articles and single files were excluded from the subsequent analysis. We analysed the selected websites (using WHO criteria) as well as the information provided, using a codebook for pro/neutral websites and a qualitative approach for the adverse ones.


Of the 89 websites selected, 54 dealt with seasonal vaccination, three with anti-H1N1 vaccination and 32 with both. Rank analysis showed that only classic websites (ones not falling in any other category) and one social network were provided on the first pages by Yahoo; 21 classic websites, six displaying popular news/articles and one blog by Google. Analysis of the selected websites revealed that the majority of them (88.8%) had a positive/neutral attitude to flu vaccination. Pro/neutral websites distinguished themselves from the adverse ones by some revealing features like greater transparency, credibility and privacy protection.


We found that the majority of the websites providing information on flu vaccination were pro/neutral and gave sufficient information. We suggest that antivaccinationist information may have been spread by a different route, such as via Web 2.0 tools, which may be more prone to the dissemination of “viral” information. The page ranking analysis revealed the crucial role of search engines regarding access to information on the Internet.

Internet; Influenza vaccine; Public health; Information