Masks? Protective gloves? Soap and water, perhaps?
You don't think they had those in 1918?
Any way you cut it the infection rates can't possibly be as bad as they were in 1918
Epidemiologists speak of the "attack rate" (the percentage of the population infected with the virus) and the "r-nought number" (the number of persons to whom each infected person can be expected to pass the virus on). Modelling the impact of a pandemic includes playing around with different factors to see how they affect these numbers.
The effectiveness and availability of antivirals and the seasonal timing of the initial outbreak are among the things that they consider, along with, yes, cultural and economic factors, infrastructure, etc. Of course. It is possible that a person not trained in epidemiology might, from the comfort of an armchair, arrive at some penetrating insight which has escaped all of the thousands of people dedicated to fine-tuning the accuracy of such forecasting methods -- but it doesn't seem very likely.
Those who would dismiss the whole matter as mere scaremongering would do well to consider that the numbers most often quoted are actually not worst-case projections, but are based on rather modest rates of attack and mortality (say 25% and 2.5% respectively). Until the pandemic virus actually emerges, it's guesswork. By way of analogy, we might note that until actually struck by a hurricane, there is no way to know for sure whether a city below sea level needs category 4 protection, or category 5 protection, or what. Currently, our level of protection against pandemic flu looks to me like somewhere between category 1 and category zip.
we're not just talking about technology here we're talking about a devastated post-war continent with no infrastructure.
The Spanish flu pandemic wasn't limited to the European continent; it was a global phenomenon. It spread quite rapidly even in places untouched by the wartime devastation (like Spain, for example). As for infrastructure, that's a bit of a two-edged sword. We've already noted that our ability to move quickly around the globe also provides efficient avenues for the spread of a virulent pathogen, but there's something else. The massive infrastructure that permits millions of people to live crammed together in densely populated cities also makes those people utterly dependent on that infrastructure staying in good working order. Modern distribution networks, with their emphasis on "just in time delivery", are fine-tuned to provide a competitive edge -- not to hold up well in the face of global catastrophe (of any kind).