Dr. Denis McCauley:

Going by the present system, it has to be above 65% or 70% to be effective. That is going by the Irish situation. The flu vaccine is available to at-risk groups and people over a certain age. That is what is necessary with the Irish dynamic. When one extends it to the whole population, that effective figure could change. As Ms Clyne said, the higher, the better. As I said earlier, any temperature that occurs in the community now will cause a lot of psychological worry and will cause economic effects. If a child or an adult has a temperature, the need to stay in quarantine at home will have economic effects as well as health effects and psychological effects. The fewer temperatures we have, the better.