Low-level restrictions in international travel (e.g. less than 70% of journeys) would have a minimal impact (Mateus et al. 2014). Even relatively high levels of travel restrictions would only delay an epidemic for a few weeks. For instance, imposing a 90% restriction on all air travel to the UK would delay the peak of a pandemic wave by only 1 to 4 weeks (Cooper et al. 2006, Mateus et al. 2014). A 99.9% travel restriction might delay a pandemic wave by 2 months (Cooper et al. 2006, Ferguson et al. 2006). d) Travel restrictions into the UK from country of origin (if it is known) will be compromised by travel into the UK from intermediate countries that develop their own epidemics. Regional travel restrictions into the UK will be increasingly disruptive for relatively little benefit. e) Putting restrictions on all air travel from the country in which the pandemic strain originates (i.e. a self-imposed or internationally imposed measure) is likely to produce delays similar to those expected for restrictions on all travel into the UK. f) If restrictions on travel from all countries which had epidemics of pandemic flu were put in place internationally, the effect could be somewhat greater: a 90% reduction might delay the spread by 3 to 4 weeks and a 99.9% effective ban by 3 to 4 months (Cooper et al. 2006). If the UK has cases early in the pandemic, then this would involve travel restrictions out of the UK.