Before revision:  Tweets favourable to vaccination accounted for 75\% of retained tweets, undecided for 14\% and unfavourablefor 11\% . Twitter activity of the Italian public health institutions was negligible. After smoothing the temporal pattern, an up-and-down trend in the favourable proportion emerged, synchronized with the switch between governments, providing clear evidence of disorientation  . Conclusion.
After revision:  Tweets favourable to vaccination accounted for 75\% of retained tweets, 70.0\% resulted favourable to vaccination, 16.5\% unfavourable, and 13.6\% undecided, respectively. The smoothed time series of polarity proportions exhibit frequent large changes in the favourable proportion emerged, synchronized with the switch between governments, providing clear evidence of disorientation . Conclusion.