The internet deals a lot with flu, but mostly talks about care and little about prevention. This is the result of a study made by Voices from the Blogs [11], a spin-off of the University of Milan, on the web-sentiment on influenza and vaccination in Italy. The researchers analysed over 700,000 online sources in Italian (Social media, Blogs, Forums, News, Wikipedia, Medicine websites, Institutional websites, etc.), published from September 1^st to November 15^th, 2016, and compared them with those published in the same period of the previous year, in both cases six weeks from the beginning of the flu vaccination campaign.

Andrea Ceron, professor at the Department of Social and Political Sciences of the University of Milan, who coordinated the survey, explains the differences found among sources: while the internet forums are more dedicated to discussions about drugs and advices to treat influenza, in social networks prevention finds more space. Drugs and care are cited in more than 56% flu-related contents, whereas prevention is mentioned only in 19.5%. Vaccine is explicitly cited only in 15.5%, a very low percentage, even if increased by almost 3 points, compared to 2015. According to the survey, the sentiment towards influenza vaccine is predominantly positive (50.2%) or neutral (38.8%). Among the favourable, 26.8% highlights the ability of vaccine to limit infection, 24.2% claims that they do not get sick anymore thanks to vaccine and 17.8% says that influenza vaccine is important for elderly people.

Moreover, older people’s attitude towards influenza vaccine seems to be more positive than in general population: the survey shows a 69% rate of positive comments, 33.7% of which saying that vaccine is important for their age group, 25.8% that it decreases risk of complications and 25.1% that it decreases mortality. Negative sentiments, however, regard side effects (50.3%), the fear that vaccine can cause more serious illnesses (26.3%) and that vaccine is only useful for very frail elderly (23.4%). Adjuvated influenza vaccine is very little mentioned, mostly on institutional sites (50.7%), blogs for elderly (25.8%) and medicine websites (23.5 %). According to the analysis, then, the awareness of the importance and safety of vaccination for preventing influenza is still far from common surveys of this kind, which analyse the public opinion expressed on social media about specific topics, can give useful insights.

Asset experts, for example, conducted an analysis [12] to identify the most influential Twitter users on Zika virus and vaccines, and also analysed the #iovaccino campaign [13] on Twitter, trying to quantify its impact. A web-sentiment analysis can help to understand better online sources of information, fears and needs of public towards vaccination, to increase vaccination awareness, to improve health communication between doctor and patient, but also between health institutions and healthcare workers, and to plan better public vaccination campaigns.