Considerable effort in recent years had been dedicated to preparing for surveillance during a pandemic and to incorporating modelling in planning in some countries. The pandemic virus was detected and isolated reasonably early, although too late for any attempt at containment. It remains unclear precisely when or where it first emerged, but the earliest human infections were detected in North America and the best estimates of the timing of emergence are variously mid-February from field epidemiology in southeast Mexico or mid-January from a molecular clock model [10] . Situational awareness during the early phase allowed quick assessment by countries, notably those affected first (Mexico, US, Canada, and Southern hemisphere temperate countries). The integration of clinical, laboratory, and epidemiologic data proved essential and gave important insights into disease severity, transmission dynamics, and anticipated impact of interventions. Focused local or national studies with analyses shared through WHO or regional bodies proved more valuable than relying on collection of primary data for analysis in some regions [2] . Although there were modelling efforts underway, only a few governments incorporated such data for policy decisions.