However, looking at things more optimistically, what I have also realized, is that we have never had more excitement and more development of vaccine science in the last two years than since the polio days. Now I'm exaggerating, of course, for effect, because obviously many vaccines, as I personally have recorded in articles, have been developed in the last 70 or so years, starting with the explosion of interest in polio vaccines in the 1950s. So a lot of work has been going on. Nevertheless the public interest in vaccination has never been greater now since the polio days.