We had antibiotics in the mid 20 's, penecilin and sulphonamides ( which back then were very toxic to the kidneys ), we have more and better antibiotics nowdays, we do have better healthcare however better healthcare is a debatable issue, better healthcare depends on where you are, you are in the American continent, yes better healthcare is available in most countries except the poorest, Europe, yes sir, Asia and Africa ? nah, I don 't think there 's "better" healthcare in most countries, at least not comparable to ours.
Also you gotta see the situation through the historical context, 1918 is only 90 years ago and still looks so far away for most of us, in 1918 we didn 't have our extra fast massive means of transportation, but in 1918 the population of the world was mostly rural, nowdays half of the population of the world live in cities ( crowded ), the healthcare systems can get overwhlemed very fast and it 's like not having them.
On the antuviral drug subject, antivirals are not only expensive, they are hard to manufacture, there are very few truely effective antiviral drugs and those that really work are very specific ( like cicloferon against viruses from the herpes family ). The only true antiviral drugs are hyperinmune serums because they contain the specific antibodies against the disease, where you obtain them ? only from blood from people who have suffered the disease so in order to obtain a cure you gotta have people who already got sick.
There may be vaccines but vaccines need to incubate before they are effective, they have to provoque the inmune system in order for it to create the antibodies and generate inmunity that takes 15 days, how long does it take to travel around the world nowdays ?
Epidemiology is not as easy at it seems, we got everything against ( time, people, resources, environment ) and when it comes to viruses precautionary measures are taken and recomended because our technology is insuficient and hasn 't developed to the point we can deal with anything. A few decades ago the hotshots of the World Health Organization predicted that by the end of the 20th century we were going to be free of most diseases, yeah right :, the only viral disease ever to be erradicated has been small pox and that didn 't happen until 1979.
Take your sanitary precautions, wash your hands regularily, don 't touch your mouth, eyes and nose unless your hands are recently washed, avoid crowded places, cover your mouth and nose and until the CDC says: ALL CLEAR, then it 's not all clear.