Influenza is a seasonal affair in temperate climates, afflicting populations reliably in the colder months. Exactly when an epidemic will peak, though, has been harder to say. In any given community, it can happen at any time between October and April (in the Northern Hemisphere). That has made planning for the brunt of an outbreak difficult.
When a ship’s crew in the Bering Sea contracted an intestinal illness in late 2012, United Parcel Service Inc. flew in medicine by helicopter. It sent $9 million of flu vaccines to Laos, too, keeping them at a constant temperature for five days across 9,000 miles.