The next severe influenza pandemic
For most people on this planet, the pandemic that started in 2009 was mostly "hype" and "unnecessary worry". Not many died, but on average death occurred to people younger than with seasonal flu. It might have started off much worse, or become more deadly after the first wave, but it didn’t. So what’s next?
The nature of the challenge
In the past 300 years, flu pandemics have happened once every 10-50 years. Each one starts when a flu virus present in non-human animals either mutates or swaps genes with another virus, and a fresh human-adapted virus emerges. Many people without specific immune experience are infected in two or more epidemic waves. Once the virus is not new for most people, we can no longer call it a pandemic and it becomes the new seasonal flu.
Pandemics are very different from each other. The 1918 pandemic, by most estimates, killed 50 million from a 2000 million global population.  The ones that started in 1957, 1968 and certainly 2009 were very different. The next one? There are some known candidate viruses, but science can’t yet predict which virus will cause it, how contagious it will be, what will be the proportion of severe and lethal cases, or which age groups will be most affected.
It’s a different fast-changing world. The globalisation of people and stuff, the specialisation of vital functions and the potential for simultaneous behaviours - buying and otherwise - may combine to make a modern deadly enough pandemic much more disruptive than past ones. Specifically, even though we can guess what proportion of severe and lethal cases will make our health-care resources even more insufficient, we have no idea how bad things have to be perceived to strongly motivate health-care providers to prioritise their own families, transport specialists to leave much of their load behind, and civil populations to start massively going by their gut feelings rather than by any official recommendation.
Actionable preparedness is cheap insurance
Safe, early, high-yield, almost print-your-own vaccines - which would give us immunity similar to the one we have for seasonal viruses - belong in the global layer of infrastructure, out of reach for most of us. The kind of mechanisms to simply make it happen for all in need are not yet visible if they exist at all.
The rest of the action is distributed in more hands:
- If we ever need to decompress and maybe even reduce the size of waves, then reduction of daily respiratory contacts works if it’s done early and non-destructively . A hundred years ago, some rural folks in India made it a habit of temporarily fanning out their population in epidemic times. Today? We can keep kids of several ages in small stable groups, trade at a distance with phone-based networks, and yes, there are options for massive temporary shelter too. For unavoidable respiratory contacts, strategies for using heat and humidity in public places  and having washable masks for all , together with ubiquitous appropriate-tech hand-washing , must be tested, documented and fine-tuned, just like well-designed ventilators , because they will be used anyway.
- Within each social group there will be an inevitable number of infections, added to and compounded with all other diseases and injuries. Every single community in the world needs real-time science for the best advice; translated video/podcast education focused on what’s frequent, severe and preventable; and generic non-patented drugs in scalable quantities.
- Finally, essential life-support services need to work for all humans. This means mapping critical infrastructure  for all locations and then getting what we need with what we have, not indefinitely which is the basis of sustainability, but now which is at the heart of dealing with emergencies.
A bad pandemic does not belong in the future our kids deserve, but our best response does. And guess what? Many of the issues outlined above have benefits beyond pandemic preparedness, and we already know how to do much of this stuff. So?
Edit- Added in 2013: Orientation tools for Macaronesian islands (broken link so use the next) and for general systemic catastrophes fwiw